Phonebay

First,2 phones come in mind with their striking similarities .HTC Touch Diamond is so similar it’s no reason to upgrade from Diamond to Touch Pro only if you are a HTC fanatic. The second ,is logically Xperia, in which we wont get in to much.
To me it’s resembling so much with Touch Diamond ,is rather boring.The HTC Touch Pro is one diamond of a looker. The gem-inspired back panel is here of course but it's less pronounced and the glossy plastic is now replaced by mat rubbery finish. This way the handset is more practical: it provides for a better grip, it'won't bruise along the edges as easily as the Diamond and finally, it doesn't attract fingerprints that much.
In addition, it's quite obvious that in reality the Touch Pro is darker than the Touch Diamond. It's closer to the pitch black color of the HTC promo shots. The somewhat cheap looking bluish grey color of the front in certain light conditions is now far less prominent.
If you don’t have a HTC Touch Diamond , you should buy this phone, personally it’s much better than Xperia and much cheaper.

The Sony Ericsson Xperia X1 spec sheet is almost identical to the one of Touch Pro. In addition they run on the same Windows Mobile Professional 6.1 OS. Now, add the fact that it's HTC that actually manufactures the X1 super phone, and you've got quite a clone war shaping up.
If you aren't dying to have a slide-out QWERTY keyboard, the options are quite clear. The HTC Touch Diamond (the Touch Pro keyboardless and much slimmer twin) and the Samsung i900 Omnia have been around struggling for the upper hand over the past three months.