Moved from modded RWA Clari-T to CIA VMB-1 monoblocks because the speakers were just too inefficient (88 dB/w/m). Note that street prices for both used are only about $100 apart and the VMB-1's are built like tanks in comparison.
Was impressed with the clarity and strength of it's 8 wpc, but imaging was poor IMO.
The 40 watt VMB-1's obviously have more power and therefore more control (mostly heard at bass frequencies). Note that chip amps, like the VMB-1, are known to synergize well with single driver speakers. Level of detail, imaging, and soundstaging are all improved over the Clari-T, especially imaging. Instruments now take on their proper size, allowing small instruments to sound small and their sound to be more focused (defined). The soundstage is much more 3D with instruments in their proper place (left/right, front/back, top/down, and in location/size relation with each other).
Unless you have truely crappy A/C, the VMB-1's (and probably any other good chip amps) IMO would smoke any of the modded Sonic Impact amps. And Dusty has stopped building VMB-1's in favor of digital designs (unfortunately at about double the price). What does that tell you how they'd compare?