G'day Bevn,
Found out early when looking into what to build the bellows or constant air discussion is like the Ford or Holden.
A few things drove my decision,
1) Cost - by the time you buy three keene trays and air supply is quite expensive. Then you still have to build the rest.
The one I'm building will cost about $6k (excluding labour). Is alot of bloody work though
2) When looking at throughput it appeared i would get more through the 2 X bellows trays than I would through 3 X keene trays
3) I was introduced to a bloke who had built 4 X 6 tray bellows units, so there is alot of knowledge available.
4) Really enjoyed Moneybox's and Nightjar articles and builds, looked like fun.
5) Bellows sound cool. 😎