What is the difference

What is the difference between an avp and avp+6. I would really like to get one of these. I have also considered the krell hts has anyone a-b these two. Any comments would be appreciated.

(sorry, I couldn't resist)
I beleive the AVP+6 has a 5.1 channel analog input, though I could be off.

FWIW If you don't need a MC input, I would buy a PAV/PDSD... they sound far better.
That's not true Kennyt, The PAV/PDSD was better than the original AVP, but is inferior to the AVP2+6