Hi,
I'm also looking at the pros and cons. I believe card based is the format of the future, smaller, lighter, higher and higher capacity cards at cheaper prices being produced. both the HDD format and Card based use Senu's favourite AVCHD format

I agree upto a certain point that it is harder to edit however the new software packages with a decent pc/mac can now handle the format without any issues and this will only get easier and better as the medium matures. IMO if you are looking to do any video editing you are going to need a decent pc, anything that's not older than 2 years should be able to handle AVCHD and you can now pick up Quad Core PC systems for below £500 I really don't think it will be an issue.
The Cams that are suitable are:
Panasonic SD9 (card)
Canon HG10 (I know HDD)
Canon HF10 -Due April (card)
I am seriously considering what is best for now and the future. The HG10 is appealing even if it is Hard drive, however I am reading differing accounts regarding if it is a true 1980 HD camera or a 1440.
The HF looks interesting however it uses a smaller sensor than the HG10. The Panny looks very nice however same issues as the SD5/7, the 3 ccds are small so not great for lower light conditions.
Personally if I was to buy one now I would either go for the HG10 or wait for the HF10, I don't like sony's attitude with their formats etc, the Panasonic looks lovely however more money than the SD5 without much improvement (I was given an SD5 however sold it as wasn't suitable for me even though it is a lovely bit of kit)
The only pro's I can see of the HF over the HG is that it is card based so smaller and lighter, and is def a full 1080p camcorder, however it is far more money and has a smaller sensor. In the end if I had to choose now I would go for the HG10, it can be picked up for below £600.