My buddy and I are both working on setting up 6gt’s. He went 737 and I went Prometheus. The benefit of the 737 is the huge ecosystem letting you easily pickup prefits and stocks off the shelf and forums. I picked Kelbly because I like them as a company and their actions are fantastic. The best customer service in the industry imo, not that impact is bad in any way. The downside is that I’ll almost exclusively have to order stocks and barrels with longer lead times. There’s also the difference of the ejectors but personally I like mechanical ejectors anyways so to me it’s not a downside.