You can look at the two largest players in the PMS industry. PMS like the mutual fund industry has largely to do with AUM's, as AUM would not go up without returns being consistent and good.
The largest is Kotak with an equity AUM base of approx 2600 crores and the next largest is ICICI Pru with a equity AUM base of approx 600 crores.
I disagree with you, big AUM does not = better performance. Reliance Mutual Fund has the largest AUM but is by no means the top performer.
A lot of the smaller players are more specialized and can provide better products. Benchmark Asset management, for example, has some very unique MF offerings.
In the PMS space, I'm a quant guy, so I've heard of two managers - ING Quant Fund and Forefront Capital Management. Both have apparently had good returns in the last few months. But verify that yourself, I don't have exact numbers.