I have a couple of 60i clips that I need to cut in to my 30p project.
Will it be a big compromise using the FCP deinterlacer vs. say revisionfx.

I did some A/B test of the FCP deinterlacer vs. revisionFX and I cant really tell the difference.

Steven

IIRC, the standard FCP deinterlacer always discards one of the fields which cuts your vertical resolution in half. Joe's Filters and Nattress both have good adaptive deinterlacers which attempt to preserve as much resolution as possible. They're reasonably priced and work as FCP plug-ins. DVfilm Maker is another option which is actually a little standalone program that processes QT files.

All of these have free trial versions, so you might want to do a little comparison on your own.

I did some A/B test of the FCP deinterlacer vs. revisionFX and I cant really tell the difference.

Steven
You'll notice the difference if you view them on an output monitor. If you've got FieldsKit as part of your Re:Vision FX package that will do the job as good as anything - It should do too, at that price.