I have the S2 and I like it a lot, but it has its cons too.
The thing I hate the most is the lower wifi signal, for example : I sat with a friend of mine on the terrace of his house, he had quite good wifi signal with his HTS Desire S, I couldnt catch the signal at all.
Another thing is that a few games crashed on me, could be an error of the app thou, I have no idea what caused it.
It also tends to overheat at times, after a 15 or 20 minutes of heavy use, its hard to make a phone call as the thing is soo fucking hot it feels like your ear is gonna melt
And the damn battery - if you plan to use apps or surf a lot, there is no chance in hell it will last longer than 12 or so hours
When using it lightly, it will take 1 and half day or maybe two days at best.
The phone is still very good I am satisfied with it, just wanted to point out the weaker parts