United face West Ham tomorrow night.
Allardyce told whufc.com: "Well I think you have to say it's as good as it's ever been because nobody normally wins the title so easily and by so big a margin, or has this much of a margin at this stage of the season. It's pretty scary what total they might actually finish with. I hope we can dent that a little bit on Wednesday night for us because Sunderland having won against Newcastle, and with all the bottom sides seeming to be picking up more points now than they have done for the rest of the season, we're still another couple of points off being absolutely safe I'd say.
"Man United have been outstanding and it's been about how their squad rotation has been his masterpiece as usual, about playing the right team at the right time. I suppose you could say that because they got knocked out of the Champions League a little sooner than usual and because they got knocked out of the FA Cup and Capital One Cup, it's given them the strength and energy to be what they are in the Barclays Premier League this year."