I have a similar feeling as yours. I've bought the AX8 to replace all my current rig but my boss DD500 (the most important part in my pedalboard) has died a few days before a gig so yesterday I tried to program the AX8 for using with my amp (only effects) and ended up buying a replacement for my delay because I couldn't get the drives sounding anywhere near my analog pedals and I don't want to take both my analog pedals and AX8 to the gig.
My style is very different from what I see from almost everyone here: I don't play metal, djent or anything like that. I play Knopfler, Gilmour, Robben Ford, etc... and my analog rig is a brownface vibroverb with some pedals I tried to replicate yesterday:
- Buffalo FX evolution: a take in the Cornish G2 muff style pedal. It's a great pedal: balanced, gritty but clear, tight bass, etc... I tried to replicate it with both the muff and the RAT. I tried everythig: change diodes, played with the cuts, the three band EQ... nothing
the Muff model just sound awful. You can make it a little better with a bit of mids and lowering a bit the bass cut but I think such a legendary model deserves a VERY better model.
- King of Tone: tried with the bluesbreaker model (in which the king of tone is based). So bright and so grainy I couldn't believe it.
In general I find that most of the drives have a lot of gain. You have to turn the gain knob in the KoT very high to make it sound like the bluesbreaker at 2 or 3 (and I remember the Marshall bluesbreaker to have less gain than the KoT). My main guitar is a strat with CS '69 pickups and have the input pad set to 12dB (for my 335 and Les Paul with antiquities).
- Wampler Plexidrive and Keeley BD-2: I tried the bluesbreaker and the two Tube Drivers. The 4 knobs sounds a bit too dark: I've played several times with the real thing and it's a bright pedal and, again, with less gain than the model. The 3 knob sounds better. But I found several of the models lacking clarity and it doesn't matter what I do that when I kick a real pedal it sounds much, much better.
On the other hands the Xotic RC and the AC (I have an AC+ and used to have a RC) seems to be very similar to the real Xotics.
I hope we could test the new clipping algorithms soon and see if things get better but I think the AX8 deserves a much better drive models. I can see myself using the AX8 with the Buffalo and either KoT or BD2 in the loop