I carry both an HD7 and a Vibrant with Active SIMs in them everywhere. I put my Unlimited Data SIM in my HD7 when I got it because of Zune Pass, but I'm about to switch it back to my Vibrant.
Audio Quality on the Vibrant is 200% better than on the HD7. You basically need headsets with the HD7. The Vibrant's sound can fill a decent sized room. Call and Speaker Phone quality ... the comparison is the same. Vibrant is wildly superior. It's like comparing a surround sound system to a pocket radio...
The HD7 is useless as a phone comapred to the Vibrant. The signal is consistently 2 bars lower and call quality is more volatile. I feel like I'm in the middle of New York on an AT&T iPhone 4 when I'm on the HD7. The Vibrant performs flawlessly.
The HD7 is only useful as a PMP IF you have a decent pair of headsets or a BT Jabra device with FM transmitter in your car (like I do).
The terrible speaker and cell radio in this thing is already enough to relegate it to backup status, but there is the issue of Apps and Services integration.
Android has better apps. After heavy use of both phones. The Android versions perform better and are more stable as well. Twitter for WP7 (even Birdsong) and Twitter for Android... the Android version runs circles around it. Same for Facebook. LinkedIn doesn't exist for WP7.
No decent IM Applications. Half-baked MMS. Can't send Videos off the device via MMS or Email.
A phone can be made better (maybe the DVP has better speakers than the HD7, and a better radio with better data speeds and call quality), but the OS is half-baked and puts way too many limitations on what you, or any app can do. This means there is a definite roadblock IRT functionality that anyone can hit on WP7 that isn't possible on some other platforms.
In addition to that, there are a ton of applications that are missing from the market, and those that are coming (that matter) won't be here for another 6 months or so.
If I was "upgrading" from a dumb/feature phone it probably wouldn't be an issue. But coming from WM/Android/WebOS and having used iPhones more than enough... It's unacceptable as a daily driver.
It has all the detriments of an AT&T iPhone in New York (poor reception/call quality/wildly flunctuating signal strength that never goes above 3 bars even standing under a 3G tower) with none of the benefits (High Quality Apps, Services Integration, Top Apps). In addition to that, the Audio Quality makes it hit and miss even as a ZuneHD replacement, and the Codec Support is just not cute compared to something like a Galaxy S device. There is no DLNA capability, either. Battery Life is not better than an iOS/Android device, so that's not an advantage.
Disclaimer: Some of these issues (in particular the reception/call quality problems) may be an issue with the phone and not the OS itself - but T-Mobile only sells one WP7 device in carrier stores so take that for what it's worth. One other person I know has an HD7 and when I asked him how he likes it he responded (I'm quoting him word for work...) "The call quality is ****, but it's okay I guess." So I'm pretty sure it's not due to having a lemon device
