Have never owned the 706 MK IIG but did have a 703+ QRP rig with W4RT duel filters and it had an excellent receiver in it. The only thing I found better at the time was after I built my K2 and it was an improvement. My 480 is a great mobile rig large display easy to read, 200w I don't run an amp, easy remote mount with Turbo Tuner and Screwdriver ant. I work quite a few stations and some DX but it's receiver is not it's strong suite my IC-7000 had a better receiver but I hated the small display some used the built in dash display for it that would be fine I guess. The new IC-7200 looks like a very interesting new mobile radio.
Mobile radios in general just because of the size and most wanting to meet a price point leave a lot to be desired in performance.
My next mobile radio will be an Elecraft KX3 (display a bit larger than the 480) as soon as the 100w amp starts production 1st quarter 2013. As it stands now it has the best numbers out there according to Sherwood's and QST's testing. I'm using one now for my QRP rig amazing so much in such a small box. It is a true SDR as such and it's feature set is unmatched also fully loaded with every option offered almost $1500 factory built.
73 de Fred N0AZZ
The License is Only Your Starting Point in Radio!
MVDX/CC of SW MO., DX Hogs, OARS, NARC, NCDXF
ARRL member, ARRL and W5YI VE
DX the thrill of the chase
""D-STAR making use of the 2/ 440m repeaters for real world Digital Voice usage around town and around the world""
" Not one of us can do what all of us can do " ** Max Lucado