The S3000 has 50 different adjustable effects built in.
They use the older type of Ram (I think it's the same type as the mpc3000) which is more expensive than the newer type the S3000 xl uses.
They seem to be virtually indestructible, I've dropped mine on the floor a couple of times, and left it switched on for days and it still works.
Pretty good for a sampler around 20 years old.
I don't have a S950 so I can't comment on that.
Here's a small part of a beat made with a mpc2000 and Synth sounds of a S3000.
https://soundcloud.com/flamprider/****And here's the built in Sine wave made into a Rhodes piano type sound with the on-board Echo
https://www.youtube.com/watch?v=WIcqL7ZP47kMy production skills aren't great but I Just thought it might be of interest to anyone interested in a S3000 and wondering what they sound like.