I think the BETA is a lot of marketing hype. Yes it is balanced, but it won't lock a bolt to the rear is large, blocks the mag release and bolt release easy access, is very heavy, and also fragile. Plus it is extremely costly.
Plus with the Beta you have to find a new place for a trigger finger to rest if you have long fingers.
I called Beta and asked if they had any plans to add last round bolt hold open-- the answer ? NO. If Colt can do it on a $30 9mm mag why not Beta on a $230 mag?
The MWG is lighter at least, affords access to the mag release, is cheaper, and I don't think it would be as prone to breakage if dripped, but I could be wrong. I think Betas will break dropped unloaded.
I had a Beta-- it's a novelty item and nice but for the price and weight obscene not holding the bolt open costs valuable time in a reload that allready has a heavy awkward magazine involved.
I'ld like to see an MWG with a CS spring to ensure against taking a set.