Since nobody answered I thought I'd at least acknowledge that there is still someone out here ;) .

I can't help you with topics a) - d) as I don't own a Mac but I might volunteer an opinion for topic e):
If I'm not mistaken the Ampfarm plug is based on the Line6 algorithms. As I own a Line6 Pod Pro and have tried the Amplitube VST I would say that the Pod is of higher quality. They are both very usable, mind you, but I still think that Line6 is closer to the real thing. I might need to spend more time with Amplitube but that's my view for now - for what it's worth.

MisterBlue.

Thanks Mr.Blue. Wow, it is hard to find PT TDM guys on here
but.. we are not alone

In related news, PODxt went rackmount last month. I wonder when a software-only version of the algorithms will come out!

Maybe the newer version of PT HD Amp Farm shall match XT.

Haven't seen the XT rack in stores but I guess I'd be tempted to trade up if I got a good deal on my Pod 2 rack ... :roll: .

Also (and I know that this will make a number of people cringe) I have to admit that I kinda like the Behringer V-AMP2. I just picked one up the other day because I needed a cheap guitar thingie for a "headphone only" practice session and I got some surprisingly good guitar tones out of it.
I hate to say it but I don't think this one is going back to the store. Also, at only $140 it's not too big of an investment ...

MisterBlue.

yes, some folks here reported that Behringer did it right.