I bought the original Magic Trackpad about 2 years ago and quickly returned it. Though massive, dragging long distances wasn't great. But the biggest issue was that it was at too sharp of an angle. I couldn't' rest my fingers on the table or mouse like I did with the Magic Mouse so you had to hover your fingers over it which quickly caused wrist fatigue. I couldn't stand it as a primary input device and couldn't' justify an $80 device just for swipes and zooms.
I've used the Magic Mouse for 5 years and am one of the few people who love it, but the new MT caught my eye because (1) it was huge, (2) had Force Touch and (3) was flatter. I picked one up at Christmas for the extended return policy as an experiment and fell in love with it. I don't really see why such a small angle shift should make a difference, but it did. I have no wrist issues when using it and it's massive surface means I have plenty of room for gestures and dragging. I've never when off the edge of the device even with dual monitors, but that may be partially related to my tracking speed. It's nicer than the Magic Mouse in the respect that I don't have to have space to move a device around. I was constantly running off my mouse pad (my magic mouse didn't "glide" well so I needed one) and i was constantly bumping it into things on my cluttered desk forcing me to lift up the mouse and move it. Plus, the mouse pad took up a lot of room and was always in the way. Not a huge deal, but a nuisance. My MacBook stays in clamshell mode for 80% of it's use so I missed out on some of the trackpads gestures. I used Better Touch Tool to turn the magic mouse into an amazing device, but i still didn't have the zoom function.
Well after trying it out for a few days I fell in love with it (and I've never really cared for trackpads in the past). The click on this device is much softer and consistent. I like the haptic feedback better than the physical click down of the old trackpads and Force Touch has been helpful for previewing links and quick look. I've now retired my Magic Mouse to special occasions when I'm working heavily with photos, intensely with spreadsheets, or doing something incredibly click-and-drag intensive that doesn't come up in ordinary use (uploading 60 files to my schools Canvas from a few dozen folders on my Mac). I've used my MM maybe 3 times this month. It sounds like a hassle to have a few occasions where you still want a mouse (at least, it did to me), but to be honest, it rarely comes up. I honestly can't believe how accustomed I've become to using it almost full time. There is an adjustment period and sometimes it still feels a little awkward (I mean I'm going on 2 months of trackpad use after 5 solid years of Magic Mouse), but I find it is much more fluid/pleasing to swipe between desktops and apps and invoke Mission Control on this massive touch surface than it was with my MM and BTT. What's funny is that my MacBook Pro doesn't have the Force Touch/Click trackpad and now I can't stand using it during that 20% of the time I'm at school and not in clamshell mode. The MacBook Pro trackpad feels so hard and limiting.
Sorry for the rant, but I was thinking of making a thread on this. It is pricy in my opinion, but worth the $129 for me. If it has caught your eye, I recommend picking one up and giving it a week. Also, I never liked "three finger drag" because I was used to three finger swipes in Lion and never changed it. It took and adjustment to move from "Double Tap without drag lock" to "Three finger drag" but I'm glad I did. It really is handy (though I wish I could set it as four-finger drag and three-finger swipe between spaces). I will also add that using three finger drag makes spreadsheet use almost as good as a mouse. In fact, not one of my 3 MM usages in this past month was for spreadsheets (and I work with a lot of spreadsheets). Once you adjust, the trackpad is an extremely efficient device, though I am glad that i have my MM in a drawer just in case.
EDIT: One other thing. The MT2 has a story of matte finish, so it doesn't get dirty as rapidly as my old Magic Mouse did, which required me wiping the surface free of smudge or grime a few times a week.
