Does the Dev help with air flow... yes I do believe it does, we did tests to help us make it the way it is now (FOR IT) not really the TM. We were focused on the filter flowing as best we could get it, this just helps the TM's out.
Many guys say it increased the TM's performance but I think it just because they may have been using a smaller filter that was just to small in the first place, so when first used it gives the impression of making the TM vac stronger....but the TM is really just the same nothing was changed on the actual TM.
I am a airflow junkie, but over time I have come to my own conclusions about how things work, like 4 2 door, 2.5, HSK, and so on.
The BIGGEST thing about the Dev filter is ease of use for the guys using it, LONGER WORK TIMES, CLEANER WASTE TANKS, NOT HAVING TO ENTER WASTE TANKS FOR BASKET.
The
Butler Box is fine really and if you have that already I would say there would be a very minimal gain if any, so I would just keep what you have, you may want to just try putting a white liner in the basket if possible, this just comes back to ease of use, much faster than washing down a basket, or waste tank filters, clogged pump outs.
I'm not talking down about my filter just giving you a honest answer.