Reasons to play SNGs as sets:

• At all tables, the blinds are the same amount. In general, there is, at most, only one difference in blind levels. For us, that means that our playing style is the same at all 6 tables. That means that you are playing weak-tight or push-fold at the same time at all tables. So you don't have to adapt to different situations while you are playing.
• The closer you get to the final stages of your SNG the more tables that are already closed. In general, there are never more than 2 tables which end up with you playing Heads-Up, when you start with six SNGs. So you can concentrate completely on these two tables.
• You have static breaks. When playing SNGs you just can't take a break for two rounds, like you can at a cash game. You're tied to your pc. So if you're playing using the successive style, you won't be able to just make a little break in between. But when you are playing in sets, this isn't a big problem for you.