Suntour used to be pretty poor, but I understand their air units are far better now.
Are you going off road with it? I have 100mm air forks on one of my MTB's, the lockout is very handy as I can keep it locked out on the road (except for part of the commute through a trading estate with a holed concrete road)
Personally, I really like 100mm travel forks on my XC bike, it's enough travel to soak up roots and small drops etc without spoiling too much of the action. They can also handle a fair bit of abuse (speaking purely for my Rokshock units,) they soak up the rocky trail at Penmachno without too much bone jarring!