AVCHD Editing Gurus

We recently bought the canon hf100 and my PC is too old to even attempt editing the avchd footage. I do not do any tinkering with computers so upgrading is not being considered and the kids will use my current machine. I need to buy a new computer and the research process has consumed me the last few weeks. We all know the great stories mac users have to say about their macs. However, after researching macs I see that apple software transcodes to AIC and there are some who insist that hd quality is degraded during this process and some that insist it is not. In the pc world, there are many editing options and according to the forums, there are a lot of bad experiences for pcs as well.

So, I am hoping to make a decision this weekend after getting some feedback from users that are having good experiences editing avchd on macs and pcs. If you are out there, can you provide your real life experiences and specifically try to explain your thoughts on pros and cons of PC vs Mac for what I want to do buy using your real life experience with your workflow.
If I go the pc route I would probably buy the new i7 2.66 (dell) or at least a 2.66 quad core (HP) with at least 4GB of RAM and a decent video card. If I go the mac route I would probably get the iMac 20 or 24 with at least 2.66 processor. Would either of these pc / mac configurations allow me to accomplish these things:

1. record at highest quality
2. easily transfer avchd footage to computer
3. I currently feel the need to permanently save my raw avchd footage but this may not be necessary.
4. edit by adding fades, effects, music, menus and titles
5. burn to standard dvd in SD for friends and burn to standard dvd in hd for my PS3. I do think I will get a bluray burner in the future.
6. I have days of raw old family footage on DVD from my old hi8 and minidvd camcorder that I would like to edit and possibly merge with the new avchd footage.

I would of course like to do all of this efficiently and with no crashes…I realize no crashes is wishful thinking but the fewer crashes the better.
If you are a pc user, what software do you use and what version of that software?
Does the video card have a big impact on stability and efficiency? I think one of the editors is optimized with nvidia cuda technology?
Are there any all-in-ones by dell or hp that can handle avchd editing?

Well, count me firmly in the MAC camp. I use both platforms and the nice thing about the MAC is that it will do the job straight out of the box. And AAC is an outstanding audio format for DVD. Some with "golden ears" may be complaining about it, but that's so small a percentage of the market (less than 1% IMHO) that it's not worth making it a deal breaker.