Sig:Xes are great amps. It's very hard to dial them in incorrectly, the controls are remarkably intuitive.
I don't find it really dry, I think of it more in terms of being a slightly different gain structure, very organic and woody/throaty as compared to say my Engls, which are compressed to hell (but sound really good).
I used to own a Soldano Avenger, and I'd say that had an even more raw sound, but it didn't have the amount of gain that the Sig:X did and was only single channel. Given that the Avenger is supposedly based off the SLO lead channel, that's something to keep in mind.
If you push it the Sig:X with a tube screamer, it will sound a lot more liquid and saturated, but will still have that raw tone underneath. Honestly though, I think you'd only need a TS if you were going for really high ultra super gainie music.
The Sig:X will keep up with the Diezel VH4 I have in terms of gain, though due to the gain structure, a lot of people might feel it's not as distorted.
I did a Sig:X video a while ago, here it is:
https://www.instagram.com/p/BylHozSnkEv ... _copy_link