First off, Epix hasn't crashed on me even once. Can't say that about some of the WinMo devices I've tried in the past. Reminds me of when I first got a Motorola Q9 to review some time back and took it on a trip with me. I distinctly remember almost losing my marbles in a United Airlines terminal somewhere when our flight was twice-delayed and I tried to take solace in reading some sports news on the Q9. Crash, crash, crash and I nearly broke out in sobs.Next, battery life is much improved over the notoriously short-on-stamina Blackjack and Blackjack II, which Epix essentially replaces. Thin may be in, but thick adds room for a beefier battery, which means you can rock the 3G a little bit longer than your iPhone-toting friends.
Beyond that, I really like the use of the optical mouse. It's not much different than the trackball that RIM and HTC have recently employed on the Curve/Pearl/Flip and G1, respectively, but it might actually be easier to use than a trackball. The optical pad can be set to full-on mouse mode or to a "sweep and pan" mode depending on the user's preferences. I found it really handy when browsing the Web and trying to click on those tiny little hotlinks that touchscreen phones are notoriously bad at dealing with. Several times I honestly forgot that Epix also had a full touchscreen, and got a kick out of remembering ... and then mashing every vritual button in sight with my thumb.
Speaking of browsing, I also installed a Beta of the Skyfire browser on Epix and it worked quite well. I wasn't quite able to "enjoy" streaming Flash videos from Hulu or YouTube (as I'd seen advertised on some forum or another), but Flash does work on Skyfire - at least in theory. Complex pages rendered very quickly via Skyfire on Epix, and I'm looking forward to playing around with the browser a little more.I still find Windows Mobile to be a clunky, annoying OS, and Samsung didn't put TouchWiz on Epix so none of the WM 6.1 experience is hidden from the user. But the actual hardware worked very well for me - at least in initial, limited testing - and the fun of using Epix itself overshadowed whatever personal bias I still harbor towards WM. 3G data worked well in Dallas and Oakland, WiFi was decently strong, and Samsung did a nice job with the camera and camera UI, in particular.