Well...for starters, you have alot of history of proven performance with the Browning BAR. I used my brother in law's father's BAR in 30.06 to drop a nice doe about ten years ago deer hunting in Wisconsin with my friends and family.
I personally have never shot the R1, though I have shouldered one at a dealer and admittedly was rather smitten with the rifle. I know alot of folks do not like the futuristic styling of the gun (same as the visceral reaction some have had for the new Browing Cynergy O/U's) Beneli is a quality product though. I am not familiar enough with the new ARGO gas system on this gun but would imagine that the recoil woould be somewhat comparable.
Call me old fashioned but I'd personally opt for the tried and true Browning BAR. Good luck!