FWIW, I made the step to BIAB and haven't moved on, at least yet. I chose to upgrade to a 20 gallon kettle thinking that it would serve me well in the future no matter what direction I chose. I now brew what I would call a hybrid mostly; I brew 11.5 gallon batches using roughly half grain BIAB and then hit my gravity target with roughly half DME. This is all done in one big kettle with a big propane burner.
For me the single biggest improvement I made was doing a full wort boil and then using an immersion chiller to cool it quickly. It's not perfect, but it's simple and I have made some very nice beers this way.
So to make a typical pale ale, I am using 9 lbs of grains in a bag in about 10 gallons of water; I could do more but the grain bag gets heavy. I complete the mash and then sparge it with 170 degree water over the kettle. I then bring it a boil, turn the fire off and add 7-9 lbs DME while stirring. I then bring it back to a boil and top up with a gallon or so aiming for about 13.25 gallons. Then chose your hop schedule and go.... Then chill aggressively with the immersion chiller. Drain into two 6.5 gallons carboys, pitch two yeasts....
The end product has been very tasty to me. And the clean up isn't too bad.
And lastly, I made this move at the same time that I moved to kegging.
Hope this is helpful somehow.