I bought the Inspire and I had the same dilemma. My reasons were purely subjective based on handling the device at the store. I also read reports of call quality issues on the Motorola. Not sure of I believed them, but I did read positive reviews did the Inspire, so it was a factor for me.
Subjectively, HTC Sense just feels polished and has relatively little unnecessary bloated. The HTC Sense Web services seem useful, such as finding your phone on the map, wiping it remotely, and ringing it from a Web browser.
My experience so far has been positive enough to make me keep the phone. I consider myself a power user though I currently have no need to root the phone.
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