My findings on this having just moved away from the 2x to an sgs2 is that the problems some ppl have with the 2x is device specific. I got one from my local CEX, and it suffered with the BSOD and random reboots constantly, didn't matter one jot which ROM was on it, it was the same. Cutting a long story short I took it back, swapped it for another one they had and it couldn't have been more different. Smoother, no reboots, no BSOD, not one. Even when running on CM7 or modaco fr18 beta 2, it was rock solid, only thing I would say, however, is that the lack of RAM showed up occasionally.
That said, I have now bought an SGS2, and it is, quite simply, the first android device that I have used (which is many, trust me) that can match IOS in terms of fluidity, even whilst running a live wallpaper too. Having 1Gb of RAM is good, you can really see the difference in use. Only thing I would say is the database write speed is still a little slow, but that's just an observation, in practice it doesn't make a great deal of difference in general use. It is a better phone, but at the price point and with the hardware on board that would be expected.
If you get an LG Optimus 2x that works, however, for the price, and a little modification from modaco, it takes some beating!
There is no spoon...