Today while I was working up Hangar 18 (I'm a metalhead at heart so there you have it Megadeth rocks!!! ) I noticed that when it comes to sweeps I sweep down but when it comes to sweeping up I kinda hammer on the notes to the chord one by one without really striking them, so for my picking hand it feels almost as A.P. but I still get the legatto sound kinda like sweeping, and you do hear the "sweep" when I go down. This seems to come naturally to me. I've always been a sucky sweeper (I can't even sweep the kitchen) so I guess my hands kinda try to find short cuts on this... soundwise I can't tell the difference and I actually sound cleaner hammering on the notes. I figure I'd share this and see if anyone else kinda works the same way.
I hope this is useful (at least to some)