Cford - not directly. I owned a 'Standard' Musician III for about 8 mos., then went back to tubes, before I then went to the NuForce 9V2SE's.
Based on what I have read about the Musician Signature version, I think it would be a tough call between it and the NuForce V2 9 SE's.
As you probably know, 'audio memory' is a very tricky thing, but if pressed I would say that the NuForce 9V2se's have more finesse and are ultimately more transparent that the STANDARD Musician III that I once owned.
Also, even though the power rating is much less than the Spectron, the 9V2SE's sound like big tube watts, and really sound like they are putting out a LOT more than their spec.'d power rating would indicate.
I could have gone either direction really, but the Nuforce's are about $1500. less expensive (retail) than the Sig. Musican III, so this was the deal maker for me personally. Also I tend to prefer a mono-block topology for various reasons.
If you needed more power and have the extra $1500., then I think the Spectron would also be a great pc. to consider.