It's no secret on this board that Making Money is my least favourite Discworld book.
I have come to the conclusion that it suffers from being a sequel. In Going Postal we didn't know how Moist was going to act in a situation. That book is a voyage of discovery for Moist - he learns who he really is.
Making Money doesn't have that. We pretty much know how Moist is going to act and he does. The only thing he really learns about himself is that he gets bored if there isn't a challenge to stimulate him. Well, he'd already discovered than in part in Going Postal.
The bad guys in Making Money aren't up to the standard of Going Postal. You never really feel that Moist gets to stretch himself. And finally, the golden golems plot just seems to fall flat.
It's not a terrible book. I've read much worse by many other authors, but of the Discorld series, for me, it's the weakest.