I currently run a SU-G700 with a set of B & W 603 S2 Anniversaries and with the 8ohm nominal power at 70 wpc and the 4 ohm load at 140 wpc, they get loud in a 16' X 15' foot room. The S2 Anniversaries are rated at 88.5 db so they're moderately efficient. The Technics has alot of "tech" in it and it is a good value for a digital amp, but it does have a full neutral sound. Couple that with the sharpness of the high end on the B & W's and recordings that are less than pristine audibly sound poor.
In contrast to that, My McIntosh MA162 (recently refurbed and happy), puts out an 'old school' warmth connected to my LS 50 metas in a 10x12 home office and they sound wonderful. Prior to the refurbishment of the MA162, I had a Rotel RA-1572 powering the LS50s and was frankly, disappointed in the harshness of the high-end (LS50's are inefficient at 84 db for a small speaker and need a solid amp to play well).
I am thinking about playing the 603 anniversaries with the Mac amp to see if there is a differential in the sound, and I added a small subwoofer as well (Cambridge Audio x301) to balance the high and low end.