No 30.5 & 31.5. Still of reference quality ?

have you considered trying the DCS Purcell upsampler with your current theta processor and transport? Around 2k used price for the upsampler

I replaced my theta data basic II and gen Va with a
mark levinson 37 and 360s. The levinson gear is
a lot more relaxed in its presentation. If nothing else
try replacing your data basic II with a cheap
(200.00 US) sony dvd player. This made a big difference
in my system and prompted my change to the levinson.

The build quality and aesthetics of the 30.6 & 31.5 are excellent. Unfortunately, technology has passed them by. Personally, I feel there are a number of other systems that better them for the same money.

I'm not sure about the 30.5 (the 360s is probably its equal) but the 31.5 I would put up against any CD transport. Maybe some SACD transports with SACD discs would sound better, but for redbook CD you might find different colors from other manufacturs and like them better for certain characteristics but the 31.5 and 360s would definitely be in the hunt. My combo easily bested the Krell CD/preamp unit that still retails for $25,000. in my home. It also sounded better in my system them a Theta Gen 5 with top of the line Theta transport (I forget the model.)