Finalzone,
I find this development in the gimp very, very encouraging. I use the gimp in my actual work flow being passionate about photography. And yes with that can see the benefits of gegl and higher bit processing. So I find this much more exciting than the single window development of 2.7 (though I think it was due time - and I like the fact it's a choice)
My only real question here is this, disabling the 'use gegl' will stop some of the stability issues? My personal guess is, without knowing the actual technical reason, I would read the 'use gegl' as being redundant and not changing one iota the actual stability? Note - I would happily be told otherwise and may just try 2.9 git again...
As I said I'm passionate about photography (and I have Bibble5 for processing photography), it's just the gimp is my final touch tool so I do care some about stability and get easily frustrated - my main reason to stay away from development versions unless it has a feature I feel I need. 32-bit is one of those....