I think that there is a definite stylistic shift between early Mieville (PSS, the Scar, the Iron Council), and later Mieville (The City & The City, Kraken, Embassytown). I really loved The City & The City, and I thought Embassytown was a very good piece of SF. Kraken I have issues with, but it's a really fun read as long as you don't stop to think about it too much. His writing has become a lot more efficient.
As for early Mieville - I liked Perdido Street Station a lot, but it was one of those books where my attention drifted a bit, and if I remember correctly (it's been a few years) it took me a while to get into it. But by the middle of the book, I really enjoyed it. The Scar was also very good, though I felt it covered some of the same ground. I really disliked Iron Council, but that has more to do with the themes than the style.
I'd generally recommend that regardless of whether you liked PSS, you'd give The City & The City a chance, but if you don't like that either, it's likely he's just not for you.