If you are undecided on whether you should get a HTC Touch PRO or HTC Touch HD (like myself), here is a very good comparison of the two device. In terms of speed, both devices look to be the similar. On the Web browsing experience, HTC Touch HD wins without doubt for its larger screen size (3.8-inch).
Video after the break.
In this video, it shows that both devices performances to be similar. If you are like me, who wants to use the device to surf the Internet, or watch video, then Touch HD will be a better choice. In this video, it did not state that the HTC Touch HD has a higher resolution camera (5 MegaPixels) as compared to Touch PRO (3.2 MegaPixels). Also, the other most significant differences is the keyboard that comes with the PRO (that Touch HD does not have).
Anyway, in my opinion, the major selling point for Touch HD is that it is the only Windows Mobile phone (at this moment) that can be directly compared to the infamous iPhone 3G.