My MMA gym stopped its judo classes because the boss felt it doesn't transfer very well and the overlap with BJJ for what is easily applicable is rather big. He claims that the only people who are dominant with judo are top level players and then still it takes a considerable amount time to convert them to MMA. In short, judo's good, but something else will prepare much quicker.
Some thought-provoking responses here. I think I'll probably be going ahead with judo.
And let me know if any of ye judokas are in Edinburgh next year.
As already said: assuming the club is worth its salt you will learn takedowns, groundwork, and submissions. That is a pretty great base for MMA, if you can't or aren't interested in just training at an MMA gym. I also think that the strong emphasis on fast, dominating groundwork with a strong top game and speedy submissions (especially transitioning quickly from throw to pin or sub) are a nice place to start for MMA as well. There seems to be a bit stronger emphasis in MMA on top position, at least from a judging and ground and pound situation.
I have been in Judo for about a year and my previous club trained about 60-70% standing and 30-40% groundwork. I wouldn't hop in the ring/cage tomorrow, but I feel that I have a good start on my grappling basics. And, really, that is about as far as you will get in any martial art that is worth its salt.
if you want Judo transferability, get a book called "Street Stoppers" by Mark Mireles.
Judo's problem for MMA is more of image because people will see a throw against a padded floor on someone who is trained to land isn't going to do that much damage and associated it with Judo. A good throw will get them in a good position for ground work which is then more associated with BJJ