if you have more than ten times the buy in for your level, i think it's wise to play the occasional game one step up, so you know what you're in for. say about 1 in 10 sng's. as you progress to 20x the buy in, play the next level up more frequently. once you hit 20x the buy in for level 2, you should be totaly done with level 1, and start moving up to level 3.

it's ok to play at different levels, just make smooth transitions... a 5 to a 50 is bad news.