To me the 403, Which I mistakenly called the "402" seems the flattest. Taller or rather the bump in he wireless ones hurts my palm after 15 minutes and I use a computer up to 14 hours a day but not for gaming. I do not know if all wireless mice have that bulbous shape or just Logitech. I can't really attribute it to simply the height I think. It is just the overall "butt" of the thing does not agree with me. I always wanted it from the 700 on just because my OCD tells me to buy the best. The truth is it is not necessarily the best. Since the 502 is the same thing, albeit corded,heavier and right handed. Some claim the 900-03 have better buttons. Rubbish, the 502 has the exact same "hinged" setup. I know because I have taken both apart multiple times. Exactly as you point out TP4, the best mouse is the most ergonomic one. Now see I feel that changes per individual though. A man with size 16 sneaker cannot take a size 10. Trying to force yourself into a good, or bad design seems like a very bad idea to me. I have no doubt your custom mouse is great for you and may be so for many others as well. Perhaps even myself. Who knows. Unfortunately there are no custom shaped mice that I know of off the shelf. Which just gave me a great idea, feel free to steal it. Why not make a mouse ut of that polycarbonate casting material. you put it in the Microwave, then hold it the way you do for a few minutes. Now you have a custom fit mouse! I imagine it would require a detachable shell. I am amazed a company has not done this.
Anyways, I find it odd you Guy's say the 403 is tall. To me it feels kind of like just a basic mouse which is a good thing. I may like it better than the 502. I want the buttons,hyper scroll and high DPI. As I said, I dislike acceleration from windows and even with the trackng on 9 in windows under about 9,000 will not cut it across 3 32" displays when wanting to barely have to move the mouse. I am not one to pick it up and such. Many people would find that too fast I am pretty sure. The 502 is just the best off the shelf fit for me with features I use. I like to tell myself the 903 is a better mouse but it is really much the same thng. Plus if it causes me pain it is simply out of the question.
you Guy's using the 403 and basic 2 buton mice are bound to be better off physically but I use the buttons and the hyper scroll. In that regard I would personally end up losing Two buttons on the 903. They know this, hence the dummy plug. Tp4, you do not use a Trackball? With you hell bent on ergonomics would have thought for sure you forgo a mouse altogether. Unless you just built that solely for gaming. I use a mouse because of the DPI speed. A L-track or Slimblade would be a huge pain here. I have my perfect mouse imagined but it does not exist. The 903 is certainly not a monetary issue I would gladly pay $500+ for the perfect device. To be honest though I cannot use the Ergodox either but as we discussed before I did not try much. I have no doubt vertical or track, ergodox, stand up table is the way to go. I am just a damn creature of habit.
What I wanted to know this time around though is if those wireless mice including the MX Master have that big camel hump in back due to the battery? Or is it for some other reason?