the Bren/Universal carrier was probably the most numerous AFV of World War 2, some estimates being that over 200,000 were built ,It was not APC , the main role of the carriers was in fact transport of weapons or materials .it was small and could traverse most types of terrain at up to 30mph,it like tracked jeep which could go where jeep could not and carry 6 men and many weapons ,it armed with many weapons (303 Bren gun or a .55 Boys ATR. MMG ,50 Browning HMGs, Besa MGs, Vickers K (VGO) MGs, PIATs ,German MG42s and 20mm Solothurm cannon ,25-40mm anti-tank guns, mortars, or Flame-throwerits , ) it were not intended as assault vehicles or "mini-tanks". There were obviously sometimes attempts to use them in this role, but the thin armour and lack of overhead protection often made this impractica ,even the germans used it to transport fast moving infantry tank hunting teams. Some such vehicles mounted a battery of multiple Panzerschreck. see : Brittiska tanks i tysk tjänst "An example of its limitations are best summed-up in the following account: On 23rd November 1942, General Clowes at Milne Bay, New Guinea ordered a small number of Bren Gun Carriers to Cape Endaiadere as direct support to American troops operating in this area. It was made clear to the Americans that the Carriers were too lightly armoured and the crews too exposed for them to be used as tanks. In addition, they lacked any overhead protection from sniper fire, shell splinters and were extremely vulnerable to flank attacks. Thus they were forced to work with infantry support. The aftermath of an attack at Cape Endaiadere on 5th December, resulted in vehicle crews being roughly handled and resulted in the abandonment of five vehicles. The supporting American infantry found they could not advance any further and the attack was called off. Sadly, it proved yet again, the futility of attempting to use inappropriate vehicles as tanks'. Taken from New South Wales Lancers Memorial Museum Webpagel.) Here is a nice article on the Universal carrier Modern Bren carriers even the author give us an idea to replace the HMMWV in us army with more modern Universal carrier.