to my way of thinking
the higher you play
the more serious the competition
$10 players will be slighty tougher than $5 players
more observant etc
if you are good winning $5 sng
then have a go at $10 sng
if successful keep going
if not move back down
always consider br management
when you are rolled for it have a go
good luck
The variance is within the players bankroll. Some do have the tendency to play somewhat loose, however your probably accustomed to adaptation of such play.
There's a small difference in my experience, but it's not so big you have to change your whole game or anything. Just stay solid, try to keep plugging your leaks and be prepared to move back down if you run bad.
its just my opinon but most sngs under $20 are filled with alot of donks and bad players once u get to the higher stakes there is higher comp from what i seen same as mtts