Someone else suggested 'big aeroplanes' don't circle fully configured for landing - utter crap. Its far easier/smarter to do that than to be reconfiguring on downwind and running checklists when you SHOULD just be flying the aircraft. I just recently had to circle in B767 sim recurrent and I did it gear down/flap 30
Was not refering to all larger aircraft in my statement, a 767 would very rarely be conducting a visual circling manuevre at 500ft agl (except in the sim). The aircraft most likely to be performing circling in marginal conditions have much less power available especially on one engine. Medium to large turbo-props and large piston engine aircraft will struggle at high weight in landing configuration.