In general I'd say stay. If the table is a good one then keep playing and keeping winning.

I think it averages out a bit in terms of play. If you've won big hands with big cards then people respect the big stack and you'll have an easy time of it. Others go into "oh he's just bullying" which is stupid reasoning in a cash game.

Either way, good play will continue to have good results.

The only potential reason for leaving I can think of is if there's are one or two players who cover your stack and are clearly good/better players.
But in general if you're looking to improve you've got to be willing to go deep against good players when necessary, just have the hand to do it and focus on getting your share of the cash off the weaker players.