Scanning negatives and positives. Microfilm scanners?

Hey guys. I shoot and self develop a lot of negatives and positives. Unfortunately, I don't have my own scanner. I either pay the shops to scan my photos or bug people to let me use their film scanners.

I do, however, have access to a bunch of microfilm scanners which take both 35mm and 120mm film. Can I use these machines as a way to preview my photos and determine if they are worth having professionally scanned?

Will the scans be accurate at all?