Firstly, we need to talk about the differences between Android 2.1 with and without the Sense UI. If you’ve looked at a Nexus One (or own one), then you probably know that the experience with the UI is a mixed bag. Some portions of the software have been dramatically cleaned up, while others seem to be left on the cutting room floor. That’s absolutely not the case with 2.1 and Sense.
Engadget has a very interesting discussion about HTC Sense on Android 2.1 which is worth reading if you, like me, are debating HTC Sense’s value on an Android device: