My first impressions were very positive. The first thing I was looking for was how responsive the user interface was. I had previously has a Windows Mobile 6.5 phone (HTC Imagio ... don't buy one!). The user interface was very slow and the phone, at time, was unusable. The HD7 is quite the opposite. I have found it as responsive as the iPhone 4 (more on my new iPhone 4 in a later post).
The phone, in general, is very enjoyable to work with. It comes with excellent email integration. Integration to Exchange was flawless. It took only a few minutes to set up. Integration to Gmail was simple as well. Web browsing is excellent, as well. The built-in Internet Explorer performs admirably.
The 'killer app' part of the phone is the integrated contacts list. You can enter your various contact list logins, such as Facebook, Windows Live, Exchange, etc... When you pull up a contact, the phone has already combined the contact information into a single contact. Also, you can get the contact's picture and status updates. The clearly differentiates the device from the iPhone. It's an excellent experience. Your user profile is easy to update as well, and updates across your various services.
If you are about to get a new phone and one of these is available, you might want to give it a shot. The phone has great potential. The apps are not there, yet, but that is only a matter of time, especially given the Nokia announcement.