I've gone through three MS Intellimouse Opticals in the past 10 years. The last one, purchased new well after they'd stopped producing them, only lasted a couple of years, so I've decided to explore alternatives. What I really like about my current mouse is that its size (121 mm long x 61 mm waist [narrowest point] x 40 mm height [highest point]) perfectly fits my hand. Plus the side buttons are in just the right place. Any suggestions on a currently-produced 5-button replacement that works with Yosemite, and that would most closely match my mouse's profile? BTW, I'd also be willing to consider a track pad if it had three programmable buttons across the top, since that would replace buttons 3, 4, and 5 on my mouse. Thanks!