I think the only benefit to sugar gliders over the squirrel gliders is that they are smaller, the rest is pretty interchangeable.
They might also be easier to find.
I'd suggest buying female squirrel gliders before the male as it can be very hard at times to find girls, and if you've already bought a male, he may be alone for some time.
Personally I love the squirrel gliders for their incredible tail over the sugar gliders, but both are gosh darn gorgeous sweet animals.
My most tame squirrel glider was an old aviary bred male. He was meant to be a young female with a Joey but I was sent the wrong animal.
He warmed up to me over about a month without really trying, and ended up constantly snuggling in my hoodie. He was so lovely. I was devastated when he passed away.
Another consideration is their smell and marking habits.
If inside the smell can be quite strong even with regular cleaning (and too much cleaning will make them mark more).
It can be highly offensive to some. I didn't love it but it was okay, my husband hated it.
The males will also continue to mark when you let them out. I'd follow him around cleaning it up, but again, hubby hated it.