I think this is NOT their best album, IMHO it their worst one (even "Kiss-Peter Criss" released in 1978 is better to "COS"!). It is more friendly to the "new generations" than to their older fans (like me), but it had no appeal on them because they look like fishes out of water, it's not their daily bread.
Anyway, if you find it at a very bargain price, get it, but don't expect to listen to some "classics" of the years to come.