Jon, I've done that too and it does work.  I've always been very careful to make sure that the two systems were fairly identical, though - I don't know if it would work if the systems were more than a little bit different.  Even two Redhat systems at different levels of up2date might be suspect, though I don't know for sure.

Tom, I've done it on 7.3 so I'm pretty sure it will work.  I'm  still looking forward to your results, though.