9 players compared to 10 whats the difference?

My own feeling is that they are different but that the most significant difference is in tourneys. You will more often be playing at tables with 7-8 players early on with a 9 player table max and you more often will have 5 players at a table and sometimes 4 pre final table merge. This means that you get more short handed play with a 9 person table tourney.

my own feeling is that it does enable you to play in slightly more hands but so small a margin as to be barely noticable. I think it becomes harder to steal the blinds in a 9 person game because there are fewer people to steal of and it is expected a lot more.

I would probably aim to play 15-20% in a 10 person MTT early on but wouldnt mind too much if i was playing 21, 22% if it was a 9 person table game. Still the playing styles of my opponents will make a bigger effect on what hands i play - i could cut myself down to 10-12 % if people were going all in every hand and the blinds were not too bad (such as a 1$ turbo on UB) or i might play 50% if i had a decent number of chips and had opponents I could bully.