I really believe 6 seats for me as begginer is the best table to play. But i have to admit my best prizes were in nine seats. I have no doubt fell more confident in 6 seats
Six persons SnG's are preferable over nine for me. Like that the range opens up and games go quicker. If I'm playing nine at a table, like the blind structure to be longer. Even with MTT, I'll opt for a six person table.
For tournaments and sng I actually prefer the full tables, not only just because the prize pool tends to be higher, but also because of the gameplay itself. With a full table you get a different variance than you do at a 6-man table.