Couple of reasons I used a reflector:
To use the Odyssey II you need to be up a stepladder to reach the EP, so the second finder down its back serves to reduce the number of 'up & downs' I need to do to find something, also when someone is at the EP & the object needs recentering I can do it without anyone needing to clamber up & down ladders.
The reflector finder also gives me the same image orientation as in the Odyssey, so if someone at the EP asks something, I have the same direction orientation view, meaning less mental gymnastics.
It also gave me the largest apeture for $ for a finder. Though the RDF did cut off any fat,
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Another plus for the correct image straight through finder is when using the scope from home. Being in central Sydney, it is a must to use binoculars to find anything because of the light pollution. This finder then gives me the same image as in the binos used first to find an area/object. Oh, so much easier!