.09s on strats can feel like .10s on les pauls, because of the shorter scale lengths on the latter, leading to reduced tension between the nut and the bridge. So like some have mentioned, it depends on the scale length of the guitar(s) you are using them on.
I started out with .09s on strats, cos I didn't have sufficient finger strength to bend properly, moved on to .095s, and now use .10s. It was quite a gradual process, but now I'm quite comfy with most 25.5" scale guitars with .10s on. I know those who can use .10s but prefer the slinky feel and tone of the .09s. After playing for sometime, it boils down to preference. I like the tension and slightly bolder tone offered by .10s.
For my 25" scale guitar e.g. PRS, I use .10s as well, and it's pretty slinky, extremely playable guitar.
I'd prob use .10s/.11s on a Les Paul. Haven't owned one before, so I'll only know next time. I don't play heavy chugging metal sorta stuff, so .10s should be suff for me.