I agree with Speedy.
The overhead join gives you an excellent opportunity to build up a picture of the circuit activity - provided obviously that itdoes not conflict with the parachute activity.
I stand to be shot down, but unless ATC instuct it, I feel that staight in approaches are a bad idea unless the circuit is deserted/very quiet. I've been badly cut up on several occasions by people doing this!
Just my humble opinion.
Iain