The PowerVR SGX540 is definitely more powerful than Adreno 205, no debating that. However, on the android platform Snapdragon processors seem to consistently perform better than the Hummingbird processors. I'm not sure what it is, but it's probably due to the fact Android has been coded using Qualcomm hardware since the beginning.
MT4G has more RAM, Micro SD Card slot, better camera, 720P video recording which is surprisingly VERY good, trackpad which is a necessity for me, dedicated camera button etc.
The aesthetics will be different per person. I do like the sleek black look of the Nexus S but the plastic is a definite con, it attracts hella fingerprints and scratches very easily. I was at the gym a few days ago on the treadmill and dropped my MT4G; the battery flew out and the phone bounced around everywhere. I was pissed at myself for letting that happen but the phone doesn't have a scratch on it anywhere! It's still flawless! That's HTC build quality for you. I do think the chrome earpiece is a little too much though, I don't mind the chrome bezel too much but after a few weeks the chrome earpiece just looks a little weird. I think the back of the phone is gorgeous especially my purple one.
Facebook
Twitter
Instagram