i admit, i am a complete idiot when it comes to HD, so I need everyone's help. Thanks in advance! I am currently considering to trade in my Panasonic PV-GS500 for either a Canon HV20 or a Sony HCR-HC7. I am wondering about two things: one is which one should I get (I know there have been discussions here, but I want individualized opinions). Second is whether you need to have HD filter lens when you buy HD. Thanks!