Comparing the BAR with the BREN I can understand as they were similar types of weapons, but throwing the '44 into the pot is like comparing chalk and cheese. Different tool for a different job.
I’ve fired all three weapons, (sadly only a few hundred rds through the '44s,) and all have their strengths and foibles.
The BAR was first envisaged as being used in ‘marching fire’ for advancing towards the German trenches in WWI.
Held at the hip, it was to fired each time the left foot hit the ground, the idea being that rds on the parapet would keep the enemy’s heads down whilst own troops advanced.
It was soon realised that a base of fire was a superior idea.
It used the standard US service cartridge of the time, the 30-06, although there was the T34, a modification for the 7.62 NATO round, produced about mid 1949 if memory serves me right, but it saw little service.
It isn’t a particularly light weapon, weighing as it does about the same as the BREN, (there are of course small differences in which models are taken for comparison.)
It has the bottom-fed action which restricts the magazine capacity to twenty rds, and when used in it’s intended role as a SAW it definitely needs that bipod !
Most BAR models were selective fire, although the 1918A2 which saw the most use in WWII and Korea, , had two rates of fire in a similar manner to the British Besa.
The BREN, also a gas operated weapon of approximately the same weight, was developed from the ZB26. The characteristic curved magazine was a result of the rimmed cases of the .303 service rounds, the original 26 used 7.92 Mauser. The L4 series were converted or manufactured for 7.62 NATO, using both straight and slightly curved mags.
It had also been designed to be used as a GPMG, with SF mount (in a 1:3 ratio) and quick change barrels.
Although it was magazine fed a good team could keep up a decent volume of fire consistent with that required in the role.
I, my contemporaries, nor any old soldiers we have spoken to have ever felt that the magazine caused any practical limitation of one’s field of view. As two of the old boys carried BRENs in North Africa and up through Italy, pausing for a ‘relaxing’ time at Cassino, I will defer to their experience although it concurs with mine.
I like the BRENs, I’m also very fond of the BARs too, they are all most enjoyable to shoot, but I would lean towards the former should I have to choose between the two for serious use.