This is my catch all category. I'm sure that there are many people that would want me to break each of these into separate categories -- but in most cases, it wouldn't make a difference (in that I am undecided on which is better, or at least they would average out).
Multi-Button Mice - whew, this is a religious hot-bed as well. I've seen some real flame-fests fought over this one. My opinions are as follows. For new users, multi-button mice are confusing and it increases your chances of selecting the wrong button (increased errors). But users can quickly jump over this mental hurdle. Multi button mice are more prone to breakage (more things to go wrong) -- but overall, mice are cheap, and don't break that often, so who cares? Certainly not me.
Power-Users often think multi-buttoned mice are neat, but most of the time I watch, they seldom use the other button(s) -- so it is more a "toy" factor than anything else. On the Mac, you can add a multi-button mouse, but talking to the people that have gotten one, they say they don't really use the other buttons very often (other than by accident) -- so is not a tremendous value for most people, and for those that it is, they can get it on the Mac.On the Mac, you can not only add multi-button mouse (2, 3, 4 or more buttons) but it also supports chording (pressing buttons in combinations to do "new" things). For those that really care about such things, the Mac would likely surpass Windows (because the mouse functionality would work Everywhere). On my PC, I have a little mouse with a special up-down button (or there is a wheel version) -- but of course it only works in a couple of Application (and won't work with WinNT), so Windows should get dinged for that (they didn't). At least when you add something to the Mac it works.
When you are a real power user, then you often use modifiers (as well as multiple buttons), and so the Macs modifiers (shift, option, command, control, caps-lock) are plenty (and as versatile as multiple buttons) -- and the use of a slight delay on contextual menus (like in Netscape Navigator for the Mac) is good enough for most people, even if there is 1/4 or 1/2 second wasted (on those rare occasions when you need contextual menus). So overall, I can't get too worked up, one way or another. Some people like multi-button mice, for beginners a single button mouse is better. That's about it.
Contextual Menus - These are neat -- but most people don't really use them that much. They are a very "occasional" kind of thing (the way most people use them). When you want them, they can be nice.
I'd give everyone a score of 2 in this category if I had to (well, maybe Be or Windows would get a 2.5, but I don't know Be enough to be sure).
Pop-Up Menus - Everyone uses them a little. I find them used more often on the MacOS than others -- but that may be because of a lack of other control types. The Macs Popup Menus are usually the clearest labeled (with the little bold arrow). But everyone has them, and they all seem to work.
Microsoft should get dinged for the combo-box (a bastardized cross breed of a pop-up menu and an edit text control), and dinged double because other people are starting to use the damn thing. It is ugly, and I hate it's half behavior -- but there are some people that like it, so I'm going to ignore the thing and hope it goes away (and I didn't factor in the "ugly value" against MS, like I should have).
Tear-off Menus - Apple has them in the standards, and some people have used them in Apps. But support was poor, and few people use them -- so the only real way to guarantee them is by third party extensions, which can cause other bugs. So I don't reward Apple for having them, because they are not used extensively enough to count. Furthermore, I think Palettes are a far better interface choice, overall.
Windows has them in a few apps, but it is on a case by case basis (not part of the OS), and I haven't seen them used in quite some time. I don't know BeOS well enough to know (and there aren't enough Apps to be sure of their usage). But I was pretty generous to Be in the "Power" index -- assuming that it did support them. NeXT really has the best implementation (hopefully this will carry over to Rhapsody).
Just so you know, I don't personally use tear-off menus very often -- nor do I think most people will. But it is a nice feature for those few who care -- and it just makes sense (even if people don't use them).
Performance - Menu performance was very important early on, say 1980's. Windows menus were far slower in updating than the Macs, enough to annoy, and the Macs menus are still "faster", but now days machines are fast enough that it no longer matters (in fact it stopped mattering about 1988). Now days, who cares? I can move back and forth quickly on any System, and the menus are not slow enough to bother me. I'm not going to worry about such nits. Microsoft is trying to cure the parity of performance, by adding animation (slide-down menus) with Windows98. I guess they felt that things were much too simple for users, and so they had to throw another useless-gratuitous option (and potential bug) in, to make users feel less comfortable. <sigh> I could award Be some bonus points, since Everything about BeOS feels fast -- but realistically, this has nothing to do with Menus.
The Mac menus do have one major flaw -- when you hold a menu down it interrupts (prevents) some other actions from happening. This is not a good implementation, and is a direct offshoot of making menus go as fast as they do. Overall, most users don't notice this behavior -- and usually what it interrupts is only display functions (not threads and other actions which can go on) -- but it is an annoyance that should have been fixed long ago (despite how difficult it may be to fix). The Mac got dinged for this in the "Power" index (otherwise I would have put it up with NeXT).
Long Menu's -
The Mac does it right -- if you have a long menu (longer than the screen), it will allow you to scroll the menu up and down.
NeXT menu's scroll to be visible, since menu's can be moved (and placed near the bottom of the screen).
Windows long menus (larger than the screen) can sometimes scroll (like the Mac always does) -- but more commonly they either get cut off, or they just wrap onto two lines (like the start menu). This latter behavior makes it very hard to follow (visually), and even harder to operate. The inconsistancy is typical Windows garbage Watch a new user grimace when they pull up a large menu, and it fills the screen -- their eye's dart all over, they look like a frightened deer in the headlights (some have run away screaming in terror). Then ask them to hit a menu, that is three columns over (or hierarchically has started on the the other side). It will take them a few tries to do it (at least). Windows got dinged for this one in the "ease of use" index.
I haven't seen the behavior on BeOS. There is a good chance that they would just cut things off (and handle it poorly) -- but if their interface and OS, isn't forcing (encouraging) really long menus (like on the Mac and Windows), then I'll give them the benefit of the doubt.
So for this whole section, I'm giving it a wash -- no one was really exceptional enough to deserve any super praise (beyond what was mentioned). And Apple got dinged (everywhere) for having Menus that block screen updates.
Mac -- SCORE: 3
NeXT -- SCORE: 3
Windows -- SCORE: 3
BeOS -- SCORE: 3