Thank you all for your answers, opinions and advice. It is true that the sampling that I have in short handed is not yet large and may be variance but I will take into account your ideas to open up my game a little more, which is really quite conservative. Again, thank you very much to everyone.
Its not like, your opening range from CO or BTN should be any different, just because there are more players at the table. However any flaws in your CO or BTN strategy will be magnified at 6-max, because you are om these positions more often, than you are at full ring, and the chance it folds around to you is also larger. So if for instance you are not comfortable to open a hand like Q9s from CO, this will be more of a problem at 6-max, because it happen relatively more often.
I am not mainly a SnG player, but based on my most recent experience on
888 Poker, I would say, that the 6-max SnGs are probably a little bit softer on average. The last two, I played, had 4-5 huge fish on them, which you typically dont see at the 9-handed tables. Besides all SnGs end up being shorthanded, so as a SnG player you definitely need to master short-handed play.