I didn't do very well in the UKCAT. I've never done very well in any similar test either - IQ tests and so on. Not sure why, but my brain doesn't seem to work that way. I found some old UKCAT papers the night before the test and was just bamboozled by the shape matching thing. It said to come up with a rule for each one, so I did, and it was the wrong rule almost all of the time. Gave the whole thing my best shot but didn't do very well in anything. Also didn't realise it was timed so tightly in terms of how many questions there were, and so I spent ages trying to figure things out when if I'd had any sense I would have just blasted it and guessed. As it was I left loads of questions unanswered, which was my own fault.
Doing practice papers and knowing to just move on would have helped a lot, I think.
Obviously having done badly I am inclined to say that the UKCAT isn't a great test, but I don't think that it's necessarily the right test for everyone. Despite a poor score, I've actually been perfectly fine at medical school (as you can guess, the BMAT was fine for me). So if only the UKCAT existed I would have been excluded when in actuality I seem to be okay!!
Thank god there is more than one type of selection. Although it is terribly skewed. So many medical schools rely on the UKCAT that if you're more of a BMAT person (is that a thing??) you've got much less choice.