I find it's a great place to go for some practice, before heading into the AKC ring but things are also different so have to be aware of that.
In the UKC ring there is much more comfort to talk, for one. I was able to visit with the judges and have a few laughs.

They have the time to privately critique your dog later too.
They consider it 'family friendly' and encourage children to get involved.
It's owner handled... so most likely you won't have any pros in there, although some do use the shows to get practice in from time to time too.
(Or even after finishing their AKC title they'll go back in the UKC ring and get their Grand Ch and/or more points in hopes to become the #1 in the nation, etc.)
Do I put more respect on an AKC title than a UKC? Absolutely... but would I judge a dog just because of that title, no. There are standards that could have become an AKC Ch easy, if someone wanted to spend the money. And there are probably a few with AKC titles, especially finishing as a puppy, that probably shouldn't hold the title either. But they paid their dues... lot of $$$$.
Someone else will have to give details about how long they've been around... but I think just about as long as AKC. And I know some folks that are VERY involved with UKC and are proud of all that goes into it. I think it's best we encourage people to do either or both. Better than nothing at all.... and it's still a competition for meeting the breed standard.
Karen