I have not used the 8125, but I used the T-Mobile MDA for about 10 days. I also used the Treo 700 for 4 days. The Treo is much more sturdy, b/c there is no slider involved. The keyboard of the 8125 is much easier to use, but you can't use it with one hand. The general consensus is that the Treo 700 is a better phone, while devices like the 8125 are better PDA's. The Treo 700 is on Verizon, and their EVDO data network is much faster than Cingular's Edge. I think Cingular has started up UTMS in certain cities, but it is still not as fast as Verizon's EVDO. Plus, in any event, the 8125 is not a UTMS compatible unit. If you like the form of the 8125, check out Verizon's VX6700 or Sprint's PPC6700 (T-Mobile's MDA is also the same thing). They are all pretty much the same unit as the Cingular 8125, except that the 6700 units run on Verizon and Sprint's super fast data network. As far as Sprint is concerned though, their customer service is horrible. But their data plans are FAR cheaper than Verizon's, which is easily the most expensive cellular provider out there. Good luck. I am also trying to decide between the Treo 700 and VX6700.
