I have a client who wants me to incorporate AVCHD footage into a video we'll be shooting in DVCPROHD, 720 24. My fear is that the resolution won't be as good in the AVCHD footage. I've also heard that the processing required in editing this codec takes much more time. Can someone advise?
Save yourself a bunch of hassle, convert all the client's footage to match your footage. Do this in compressor. If their footage is 29.97 you will have to do some test to see if your convert to 24p is acceptable, if this needs to be done you most likely will need to use frame control to do the retiming, this will add a lot of time to the process. If your client is paying for your time (and they should be) none of this is a problem, it is just part of the process. Most people convert this to ProRes but since you are editing in DVCProHD I would match it to that in this case.
You DO NOT want to bring the AVCHD clips into FCP.