I will recheck the model. I did a cursory check this morning and nothing appeared amiss. When I get back to main HQ I will get the amp out and compare.It very well could be user error on my part and I haven't rolled back to v15 for a fresh comparison, but I'm also struggling with this model in Cygnus. I always play my real DS through a 16 ohm cab because I prefer the tone and feel compared to 4 or 8 ohms. It really is a very noticeable difference even when using the same type of speaker, it's a cool and sometimes annoying quirk of the amp. With the model I feel like I'm having to pull the bass back even lower and boost the treble or presence higher than in Ares. On the other hand, Cygnus is pretty much dead nuts on compared to my BE, AC20 and Ecstasy.
Remember there are two versions. Dirty Shirley 2 is the brighter of the two (has a 2.2nF cathode cap instead of 4.7nF).