Sony Blue Ray: S5000es vs S2000es

I have the 2000es which is driving me crazy with extremely slow load times and inconsistent performance. The picture and sound are great, when they work. Player seems almost too sensitive to a less than perfect disc.

I'm wondering if these problems were fixed with the next-generation 5000es or whether there is better performance to be found with another brand/player. The PS3 is not a consideration.

Thanks for your assistance.