I would hang on to your Sensation until T-Mobile gets some new hardware. I have both a Sensation and a HD7. Mango runs flawlessly on the HD7. It does everything my Sensation does, but better (with the exception of Flash and WiFi tethering). But in hand, the Sensation feels absolutely amazing. I'm hoping to have the Titan or something nice from Nokia land on T-Mobile. Someone will buy it and then demand an Android device, and I will come to their rescue.
WP7 is better than Android or iOS. Just my .02.
Sent from my HTC Sensation XE with Beats Audio using XDA App
Current Phone: Nexus 4
Retired: GS3, HTC One S, HTC 8X, Galaxy Note, Galaxy Nexus, Lumia 710, HTC Radar, Focus, DVP, HD7, Sensation, G2X, Galaxy S, G2, Nexus One, HD2, Touch Pro2, N97 mini, Touch Diamond2, Touch Pro, iPhone, G1, Tilt, MDA, Dash, HP 6315, Treo 600
If you build it, they will flash.