I still love my 11R too! The Pod HD 500 might be the perfect compliment to the 11R because unlike it's other Line 6 predecessors (e.g. Pod XL Live), it is a full blown Midi controller plus you get many cool effects that 11R doesn't have - stereo delay, reverb etc. You could use the FX loop in either unit to pair the two together.

So the real question remains, are the amp/cab models significantly better then previous PODs, and are they comparable (or better) than the models in the 11R or Axe-FX?

Speaking for some creature comforts, I'm not real fond of having audio cables/connections on the floor, it's really nice having my 11R in my rack. 2nd, I'm glad the Pod 500 HD has an RCA type S/PDIF out, but I really appreciate the AES Digital output on the 11R - it's just more professional in my opinion. Finally, the POD 500 HD isn't really a recording interface in the same way the 11R is with Pro Tools, although it does have audio drivers via USB. Getting Pro Tools LE software with 11R was kind of the icing on the cake in my situation.