I have allot of Gliptone products. Most of them are relegated to back-up products or get used in places that I wouldn't want to waste my expensive stuff. There leather care products are among some of the best I've ever used though.
I also like their clay. It's a bit of a different texture than the other stuff I've used and it seems to do a really good job of pulling out contaminants. My only complaint is that if you don't use allot of lube with it, it sticks to the body a little more than the other brands I've used. Overall, its a good product and if you can get it cheap, its worth it.
The Streetrod Store in West Berlin, NJ is the cheapest place to get Gliptone products that I've found.