Need your inputs - Leaving HT to 2ch

Please reply in order 1, 2, 3.

1/ Advise:
If someone already have a "decent" 5.1 HT set up but because 98% of their time is now listening to 2-ch music via their pre/pro, how'd you convince them stepping away from their complete HT set up and move to pure 2-ch?

2/ Prefer:
What would be an moderate 2-ch system that can be called as an upgrade (in sound quality) if their HT's is:
5.1 Pre/pro: Anthem AVM-30 ($3K)
Amp: Anthem A5 ($2.5K) (180wpc x5)

3/ Opinion:
If their speakers are very easy to drive, can some good /great integrated amp out perform their Anthems?

Cheers,