iQ Drive

Has anyone had any experience with the Frigidaire, Tappan, Maytag 
Westinghouse (Nordyne) Seer 23 iQ Drive Compressor and furnace.  The 
compressor can ramp down to 900 rpm with an inverter. I believe that the 
condensor fan also is variable along with the furnace fan. Is it worth 
the cost differential over say a 16 Seer or 19 Seer 2 speed scroll as 
far as long term payback. Inverter technology is hardly new being around 
for many years. One advantage mentioned is that it is not so large 
compared to some units with Seer in the 20's, also mentioned is extreme 
quietness.

Al