My sensation 4G boot time is almost 70sec with lot of T-Mobile stuff, is there a way I can improve my boot time.
Custom ROM. I just flashed Bulletproof and my boot time has gone down significantly - I don't even see the "Loading" popup if I unlock immediately after boot.
Assuming you're already S-OFF and rooted through this guide, go ahead ahead and pick a ROM from XDA Developers. Each ROM thread will have specific instructions on how to install. If you get stuck, just post here and I/someone else will help you out.
Note: if you want to flash non T-Mobile aka European ROMs, you'll need to debrand your phone using SuperCID.