Having owned both the BAR and Remington 742, I vote for the former...
The 742/7400/4 all base their ancestry on the venerably Remington Model 870 pump shotgun, right down to the removable trigger group. I own, and like, my 870, but converting it to a gas auto rifle left something out of the mix. I also had the opportunity to work on the later Remington, the 7400, and it was a pain, also. The 7400 eventually had to go to Remington for a new bolt assembly, the gun never fed rounds properly from the day it left the factory.
As for the Browning autoloader, to be fair, there has been a bit of product improvement in that model over the years, too. Things like the nylon/teflon recoil buffer in the rear of the receiver, a deeper magazine that allows one more round, a bolt release lever, and most recently, the alloy receiver and synthetic stock. (Not really sure the alloy receiver is the greatest thing, but hey, the M16 did ok with one...) The gas system is fairly straightforward, and requires minimal maintenance. And the trigger, oh, my, why don't they make triggers like that in more of today's litigation-prone industry? It's a thing of beauty.
I've really only had one gripe with my BAR in .30-06, I had to buy small base sizing dies because the chamber in the gun was so tight, I had trouble feeding it my normal .30-06 handloads that went just fine into my M1, M1903A1, and M1903A4.
This spare project gun will probably wear a modified McMillan stock, and a military BAR magazine, when and if I ever get around to rebuilding the darned thing...
