Previous Bitfountain (aka "ASICMiner") products did not support long polling, but it is certainly beneficial and perhaps worth adding to BFGMiner.
That would be great if you could - currently running the Cube through slush's proxy seems a little more efficient than through bfg's - but I'd rather use bfg.
Same here, I agree with HellDiverUK, if longpoll support could be added to BFGMiner that would be awesome. Thanks for all your hard work on this program Luke-Jr, I enjoy using it.