Playing multiple limits

[bdubs]

I was wondering what everyone's opinion is on playing multiple limits at the same time. For example, playing 2 5/10 and 2 3/6 games at the same time.

If my bankroll is large enough to play on 4 5/10s am I doing myself an injustice by playing below 5/10? My reasoning for this is if I go on a upswing on a 3/6 table while going on a downswing at a 5/10 then I am cheating myself out of a fairly significant sum of money.

Thanks as always!