krell KSA-250 or KSA-200s

i have just sold my KSA-150 to upgrade to either a KSA-250 or a KSA-200s. i'm looking for more power and i'm on a limited budget. both amps seem to go for around the same price but i'm not sure which is the better choice.

please advise,
The 250 will have better bass slam, it was the first Krell I ever bought. Then I sold it for a 200S and I wondered where my bass went. Krell told me the size of the transformer would be closer to the 300S, so I bought that and loved it ever since. The "S" series has a nicer mid to high frequency presentation IMHO. Happy listening :-)
If you liked the sound of the 150, get the 250. The 200s is definitely more neutral than the 250, but I always felt the KSA 150/250 amps were, along with their predecessors, the KSA 80 and 200, the best-sounding of the Krell amps because they were less sterile-sounding than the later versions (OK, they are colored in comparison and probably have more "character"). Both should have more than enough power to drive anything you have, although the 250 has a little more "oomph".
I like the Ksa-250, it is one of the best amps ever made by Krell. The 250 has much better midrange than the smaller 150, the downside, more heat. Krell still has great service on these amps should you ever need it and can change over to monoblock on the 150/250 models. I have a Ksa-250, IMHO, it is better sounding amp than the 200s and beats out the big 300s also but with less power than the big 300s.
I have never heard the KSA200S, but have owned the KSA250, the KSA300S, and the FPB300.

The 300S was definitely more refined than the 250, but if you can afford the 300S, I would hold off and go for the FPB300 (not the 200) which is not much more expensive and blows away the 300S especially in the mid and highs. I would say the bass is about the same.

I hope I have helped a little. If you have more questions and wish to contact me, please do so.