I have had the T since release date... and its an awesome phone. The JB update made it a much greater device. True battery might not last that much on heavy usage. Ive managed to drain from 100 to 0 in around 4 hours of full screen on time while multitasking.
Recently I have a SP with me which allowed me to compare the two properly. The curved design of the T is really pleasing on the hand when holding the T than the SP.
Also multitasking seems much smoother on the T. Free ram on JB of T is around 802MB whereas SP is around 766MB or so.
Though I didnt like the very small notification LED on the T, in a way it provides it with the elegance which I realised after witnessing the LED's of the SP. Additionally, feel the build quality of the T is better than the SP.
I also moved from a Arc S after 6 months of usage to the T. I will definitely recommend the T to anyone over the SP.
On a positive note for SP, though i've seen many complaints on touch issues, I haven't had any, so far on horizontal usage or usage while charging (through PC / AC adapter).
And the glove mode is really cool! can use the device with a gap between the finger and screen.
Current : Xperia T, Nokia N900
History : Xperia Arc S