All camcorders based on AVCHD (the old HDD ones included) will suffer from the same problems caused by the codec.
Let me give you an example :
Standard definition DV footage captured on a miniDV tape = 25Mbs/sec
High definition HDV footage captured on a miniDV tape = 25Mbs/sec
AVCHD footage captured on a HDD/SD card = 13Mbs/sec (I believe that is correct).
The loss in available bandwidth acounts for a significant drop in quality compared to HDV and especially DV based cameras.
I've been researching a digital video cam purchase for a couple weeks, so I would like to point out that while most AVCHD cams record at a max of 13mbps there are one or two that go up to 15mbps, and more importantly the spec/codec allows for 25mbps.
If you were doing raw HD DV to AVC and MPEG2 conversions you would probably get better quality out of AVC at 13mbps than MPEG2 at 25. Just a guess, but it's just a much better codec, especially when you are using the more advanced encoder options.
However, camcorders aren't doing a post record encode like that - they are doing a real time recording and I think the weakness we're seeing from AVCHD vs. HDV is a result of realtime MPEG2 encoders being significantly ahead of realtime AVC encoders. Once AVC catches up (MPEG2 has a pretty big head start and requires a lot less power to start with) 13mbps AVCHD may start to surpass HDV.
I'd only choose an AVCHD camera if I was planning on doing no editing (or very minimal cuts). AVCHD is more of a delivery format, it can be editied but there will be a lot more degradation.
HDV and AVCHD are both transcoded into AIC (Apple Intermediate Codec) when you import into your Mac for any editing. Meaning that once you get to the editing phase they will both behave exactly the same (the quality you have to work with will be different, but anything you can do to HDV you can do to AVCHD). HDV uses MPEG2 compression which isn't a whole let better for editing that h264/AVC is.
Now, I probably sound like a fan of the AVCHD format... however, I've decided I'll be buying an HDV camcorder (unless a GREAT deal on a Panasonic HDC-S1 comes up). I think that the general sentiment of AVCHD not being quite ready for prime time is probably true, but I just think it's due to technical constraints, not an inherent flaw in the codec or system.
I also don't like the fact that an hour of record time will cost me $30-40. It's reusable of course, but if I'm on vacation and want to have 12 hours of record time for the week which I can then edit and catalog when I get home, I'd have to buy 6 8gb SD cards, which will set me back at least $450. An equivalent amount of tape will run me $40 or so. The flash cards are a bit more reusable, once you back up the footage to DVD-R or whatever, but it'll take quite awhile for the AVCHD + SD cards to balance out with HDV in cost/hour.