Shows are representative of what you found on line. In both cases there are the good ones and the bad ones.

What I recommend until you become familiar with the vendors at your local show (which generally tend to be the same) is to get the vendors list and look them up on the BOI.

More often than not breeders at shows also have an online presence and reputation.

As for the breeders that only do shows and don't seem to have any online presence or rep, their animals and a 5 to 10 min conversation should allow you to determine if they are someone you want to buy from or not.