I have used all the popular makes and have to say that Promatic have worked very hard to try and get the Lion's share of the market.
Without doubt their Super Sporter is an exceptional trap for robustness, and reliability.
BUT I have Laporte's and Bidwell's that have never given a minutes trouble.
Bowman are good but did have a stupid design flaw with the early ones, easily solved with a drill and a grease nipple. But all of them really are value for money.
If I had to buy a new trap now I would go for Laporte, because with their deal on a pallet of clays with a new trap by the time you have retailed the clays you get the trap practically free of charge.
If I was a small club or an individual just starting I would certainly talk to all of the manufacturers to find the best deal.