I went with the Motech centerstand. In addition to always having a stand for mx wherever it may be needed, it's also a good idea if you have to park on hot asphalt. It puts more weight on the front tire and distributes the rest over two pads that are both about the same size as the one on the kickstand.
As for the theoretical disadvantages; I didn't weigh it before I installed it, but I would guess that it goes about 7 lbs. The 10 lb shipping weight includes a bunch of hardware that is either not necessary or replaces what is already on the bike. It's certainly not enough to be noticed unless you're in a real competition. And you'll drag the pegs way before the stand touches down, so there's absolutely no cornering disadvantage.
Pit Bull front and rear stands. Never had the need for a centerstand, even on an 7,500 mile cross country trip. Lubing the chain was a minor PITA what with having to spray, move bike, spray... Maybe I was just lucky.