It's a shame the stock Line6 amps/cabs are so limited. I actually bought an old toneport ux2 to improve on my very old m-audio interface and for access to the (free) extra models. With very little fuss I created the best guitar amp I've managed in Reason. Alternate panning through parallel channels and reverb/delay on the shared output bus gave it the extra oomph needed.
I tried to make a similar template for my brother using reason 6 and the stock line 6 amp (I forget the name) and it was difficult using a not so good starting point. I understand them limiting it but I think it's so limited to be not really that usable.
I've followed many tutorials about building combinators with screams and so forth and not come up with such a good sound. Not everyone wants to buy line6 interfaces just to get access to the extra models. Perhaps there's a tie in with PH and line6? Otherwise I would have thought we'd have seen alternate guitar amp REs on the first day the shop opened.