I wasnt suggesting calling lots of all ins.

I didnt realise you were talking about good players. Where I play the players are dreadful and will call with weak Kings e.t.c - so if you have a hand such as K2 they wouldnt lay down K4+ therefore you are far more likely to get a caller.

I suppose it isnt bullying the bubble - its defending my stack against the nutters and stealing the occasional blind in the right spot.

With over 5000 chips it doesnt really matter whether you enter heads up with 5000 vs 3000 or 6000 vs 2000 - obviously the second is MUCH more preferable, but I wouldnt risk going below half the chips to get to that position.