Looking for mouse recommendations

[Phanx]

I've been using a basic Microsoft Intellimouse Optical 5-button mouse for the last 10 years, and while it still works great, I'm looking to upgrade. However, I'm having trouble finding a modern mouse that I don't hate, and I'm hoping you guys might have some ideas.

Based on my experience using my own mouse vs using other people's mice, my criteria are:

1. Back and foward buttons on opposite sides of the mouse.
2. Symmetrical shape.
   I'm strictly right-handed, but every "ergonomic" mouse shaped for the right hand I've ever used has driven me nuts.
3. Large size and decent (or adjustable) weight.
   Original Xbox controller was the best, 'nuff said.
4. At least 5 buttons, but does not have a whole numpad on the side.
   I am not really that excited about 6+ buttons, since apparently Windows doesn't support them as mouse buttons, and the software just fakes it by binding those buttons to infrequently used keys like PageUp/PageDown or running a macro, neither of which can completely replace a mouse button in WoW due to the way it handles clicks vs keypresses... unless you use the Official WoW Gaming Mouse with WoW art all over it and 34904832 buttons on the side, and then Blizzard will go along with the mouse software and agree that they're real mouse buttons.
5. Not wireless.

I've already tried the Razer Lachesis and the SteelSeries Sensei, and sent them both back.

The SteelSeries was nice and big, with a classic mouse shape and buttons that weren't too stiff but still had good tactile feedback when clicked. On the down side, the side buttons were too far back (I could get the left ones by lifting and folding my thumb, but the right ones were impossible to get without totally repositioning my hand), the mouse wheel was a little stiff, and the slippery chrome finish was too shiny and, well, slippery.

The Razer looked cool but the long, flat shape was actually pretty annoying to use. The side buttons were way too stiff, and the rectangular sides coupled with the top of the mouse being much wider than the bottom meant that it was really hard to reach the right-side buttons (ring/pinky fingers). It also was much lighter than the SteelSeries, though I did like the matte black slightly-rubbery finish better.

Also, the extra buttons on both led me to discover the Windows-only-supports-5-mouse-buttons issue described in #4 above. While the price is not really an issue, I do feel like it's a waste of money to spend $30+ more for extra buttons when I can't fully utilize them.

I might try the SteelSeries Kana, which just has one button on each side. Based on the product photos though, I'm concerned that the side buttons are also going to be too far back.

Any ideas?