I know a few people that have them. They seem like nice cases, and from what I understand the maker is a pretty nice guy to deal with. They seem to be extremely durable and well made, but also pretty heavy. Just my $0.02 One of the Azer's here owns one and might be able to tell you more if you PM him. His screen name is Gum9Ball. I think our own Jimmy M. has one also.
I have two OnQ cases, I just got my second this week, a 1x2 in black lizard print. Garth is a great guy to work with, very thorough and has a high level of quality, not to mention a value when compared to other makers. I strongly recommend him!!
I own a 24G. Got it about 3 months ago. Great case for the money. All hand made, nice leather and top quality fittings. It is a little difficult to get stuff in and out of the pockets. May sound a little dorky but I bought a small mesh pouch for $7 at a luggage store that clips onto the towel clip. I find this easier to use.
The case will lean up nice against a wall and the indentation where the pockets attach to the case makes a nice cue holder. The flat surface on top of the pockets is also useful to lay your chalk or talc bottle. I find this helpful during league play in the bars. I can keep my cues and case close to the table and not have to worry about them being knocked over or banged into by the waitresses or other players.
The case weights about 5 pounds because of the weight of the leather.
Cues can be stored up or down. This helps when you have to move from table to table when playing in tournaments. You can put the cues into the case fully assembled. Also helps when assembling or taking apart your cue.
I own a OnQ 3x6 case and have had it for more than 3 years and still looks brand new. All I have to say are good things about this case and the builder,Garth Baer. He updated a couple of the features on the case at his suggestion at no cost to me, he takes pride in his craftsmanship and stands behind his work. I highly recommend his cases and work.
Hope this does not sound too much like an ad campaign but this is one place in the pool world you can get a true value.