I have been with customers to see horses there. They are generally young and very green but safe. The owner does try very hard to match people with the correct horse and gives you lots of time to try and isn't pushy.
The one my customer bought wasn't her first choice, (he failed the vet although the vet said that was very unusual for a horse at that yard). I felt as a first time owner she took on a lot (very young 4yo) but a year on and with a lot of help things are going much better and I think she will end up with a super horse.
Go with your eyes open and someone to help advise you.