Advice on Jeff Rowland 8Ti

I wish to buy a used Jeff Rowland 8Ti. Could anybody please offer any advice on the power amp. In particular, will the performance greatly improve with the use of an additional DC power unit.
the jrdg model 8 is no longer in production (altho it's listed as a "current" product on thier website). hence, unless the seller already has a battery unit, they may be hard to come by. the battery unit does lower the noise floor and provide a "blacker" background. i've never purchased a battery for my modified 8ti, tho, because its use cuts in half the power output and i need the 400 watts/channel the "ac-powered" amp produces into my speakers' nominal 4 ohm load. -cfb
You might want to hear an earlier version with the choke power supply, if you can feed it with clean AC then you might prefer the sound to the more recent versions with the dual mono supply.What speakers are you planning on driving with the 8?