I'm getting ready to trade my Sony HC1 for a Canon HV20. Am I going to have problems playing tapes made with the HC1 in the HV20? Both are 1080i so I'd think I shouldn't have any issue, but I just wanted to check while I can still easily put the raw footage onto a hard drive.

It's not the HDV format you need to be concerned about. What could cause problems is the minute alignment changes between decks of different brands and ages. Try to get your critical stuff onto the hard drive before you trade cameras.