HTC Titan review

The HTC Titan is the bigger brother of the HTC radar and the Window Phone version of the Android running HTC Sensation XL albeit without Beats audio technology.
Click on the above link to see how the Titan fares.
iPhone 4S vs. iPhone 4 and Galaxy S II, Bionic and Titan

For differences between iPhone 4 and the iPhone 4S Engadget has a nice comparison here. On the whole, a dual core processor, 8 megapixel camera and ability to use Siri.
For a comparison with its rivals Engadget has another nice chart that can be seen on the above link.
HTC Titan and Radar WP7 Mango phones hands on

HTC have revealed their Windows Phone 7 (WP7) Mango phones line up. The announcement back in June for the update is Microsoft’s attempt to revive its flagging phone OS in the wake of the increasing domination of Android and iOS. Despite Microsoft’s close tie in with Nokia in developing new Windows handsets, other manufacturers continue to support WP7. HTC was amongst the first to release WP7 handsets. Despite its success with Android and new phones such as Vigor ,a special edition of its Sensation and another Android Tablet, HTC is about to release new WP7 phones.
HTC are releasing two handsets, the Titan and Radar.
Titan

The high-end Titan has a 4.7-inch SLCD display, 8MP rear camera and 1.3MP front-facing snapper, a single-core 1.5GHz processor, 512MB of RAM and up to 16GB of fixed flash storage.
Radar

The Radar entry level has a more managable 3.8-inch LCD, 1GHz processor clock speed, 5MP rear camera resolution, RAM and maximum 8GB fixed storage.
Click on the above link for more.