Takes a while to get used to the ball toss outside, with no roof to contextualize where the ball is.
I like playing indoors as it pimps up the opponents game and makes it more enjoyable, the kind of players who would just be a joke outside. They find it easier, so there is more pace, better length so it feels like you are playind someone half decent.
Most indoor lighting is poor. I watched Soderling play in a $200000 event where the lux was 180, well I saw Soderling but no one saw the ball. The tournament was never held there again.
Too hot in the summer indoors.
Pressurised bubbles are fun - expletives echo round the whole facility.