There are a lot of jigs on the market today and most of them look like they do the job. I don't have any advise rather than my opinion. I was in the market myself for one of the best and ended up with the PC 24" Omnijig. It has some features like the Leigh and a couple of others but I like the idea of set and forget. The set up blocks are used for certain applications and exact repeatability results when changing from set up to set up. I have not had time to really test this jig to it's full potential yet but I like what I see so far. This is my third dovetail jig like this and my second PC. This things fairly large and has some heft to it, but that's what I like about it. I hate cheap stuff! So far so good.I would love to share more info with you as to this is an expensive purchase for most. If you like simple,Keller has a jig that I almost bought before this PC and now Leigh just came out with their R9 which looks like the same principle.
Cheers,
Greg