Brief A/B with an LMIII through a Berg AE410... pretty much what you woudl expect. Streamliner was deeper, smoother through the mids, and killed the LM in volume. The LM could go inherently "textured" in the mids to a warm sound via the VLE, but it didn't have the depth of tone that the SL has. LMIII has "more EQ", but frankly I found (and continue to find) the Streamliner's EQ network to be incredibly well thought out and extremely usable.
Ditto with my experience with my LMII!
I just finished up a wonderful hang with the great Mike Harrington (I always am amazed at the amazing players in Detroit... Fredericks at the house yesterday, Harrington today... who knows who tomorrow!). He brought over his Thunderfunk 750a. Great head... all the good of the 550b plus a more open, less compressed low end.
TOTALLY different voicing from the Streamliner. Volume capability seemed about the same (both amps impressive), but the Streamliner had massively more low end, a much smoother inherent mid response, and a sweeter top end. The TF750a was tighter and punchier, and sounded more like a much bigger Markbass F500 (we A/B'd those two heads, and while the TF750b not surprisingly topped the F500 in volume and 'open low end', the general tone profile was quite similar). I would guess the Shuttle Max 9 would be the Genz product of choice for those who are using Thunderfunks but want to lighten the load or whatever.
I would guess the Streamliner 900 would be more appropriate for the DB750 guys looking to lighten the load versus the TF750a, which really is a different thing.... no give, no really tubey big low end... more of a very nice, warm, very punchy, tight, loud amp. I actually dug it a lot, and it was reasonably small and relatively lightweight.
With the P Bass, it was ALL Streamliner though IMO. With our J basses, more 'two different flavors of loud and good'
