I built a Tube Pre block mimicking the SLO power section and after shooting it out against the x88 power amp sim, it is largely a wash. The SLO has ever so slightly more low end girth,
(that’s what she said) but the x88 sim has a touch more cut. (Probably from the slight bit less low end) I did a mix with them back to back and I doubt anyone would notice unless you told them.
I wonder what they used for the x88 power amp sim. (I’m assuming not the SLO since they said it was a 120w pa) In either event, it holds up.