Well I ended up popping those Matchless Celestions in a 2x12 I had, and swapped in some TDS transformers in the amp.  Bill Wood is a great guy, by the way.

Man this amp rocks!  Beautiful cleans and gnarly overdrive.  I'd say the transformers helped the highs a little bit, but overall it could also be placebo effect.  The speakers sound great, but I'd bet a normal set of Celestions would do the job just as well especially after some time went by.

The PPIMV works great as per usual.  I have a few amps with that type of master volume.

I've been using it with my Kleinulator in the loop to great effect.  My delay pedals didn't like the loop without the Kleinulator.  Overall I'm extremely happy with this amp and am very glad to add her to the stable.

Just got my DZ30 Head from Nik about a week ago.  I'm reviving this thread.

Was your DZ30 stock at the time of this post?  I'm wondering if a transformer swap would close that gap.

I've only played mine through a Thiele 1x12 with a Mesa branded EVM12L so far, but this is a sweet amp.  I have the real Matchless mismatched pair coming UPS as we speak.