The main problem we find with doing certain rides solo is that a lot of them have pre-shows and can be quite long.
Remember my wife going on the Shrek ride last August and she was gone over 3/4 of an hour.
So if there is a queue we find it doubly hard and often never bother with rides that have a fair wait involved.
Test Track was similar, I was very keen to try it but the wait was 30 minutes and just wouldn't have been fair - at least on Joshua's rides we can plan in so that we can get on them, several times in most instances.
Rode Woody Woodpecker 6 times on the run with Josh last March