First obvious point: editting in S&F was embarassing. Don't know if any more needs to be said on that topic, but feel free.
Now for my real point: I have 3 of the class books, S&F, T&B, and DoF. The main reason I purchased them was for the prestige classes, although the spells were also important. I found the prestige classes in T&B quite interesting, even if many of them have absolutely no place in any campaign I would run. On the contrary, I was very disappointed in the DoF and S&F prestige classes. Although both had some good classes, many of them seemed extremely uninspired. IMHO, the problem is that many of the prestige classes were made very generic, just a collection of special abilities with a name tacked on. I'd rather see pretige classes that fill some specific specialized role in their world (e.g. how about a Healer of Pelor, rather than a templar). Even if I don't use that specific deity, the class might be interesting enough to tailor for my own campaign.