The speaker sim thingie is because I'm lazy to go setup some sort of sound proof recording room / isolation box... so it's how I usually do my
amateur home recordings.
I've used a 5 watt tube amp (Gries 5) with the Openhaus with no deficiency in tone. Then again, the Gries 5 has ridiculous head room... playing with a Dimarzio X2N does not overdrive it(!).
Of course, to maximise the tone - you'd want headroom, 12" speakers, 16 x 12" stacks, arena space, ear killing volume, etc etc.
And Ed would want his customers to experience the best. Which is very good. That said, the Openhaus still allows for great high gain tone at bedroom volume with less-than-recommended tools.
By the way, the how-to-use instructions for the Openhaus applies to any high gain pedal. Try the seventheaven on a Roland Microcube for giggles. Or a Boss MT-2 on mesa boogie dual rec with 4x12 cabs for +10 respect to Boss. Okay, I'm kind of exaggerating with the MT-2 but you get the idea. heh.
That said, Wasp... there's something worth noting. A dirt box isn't just about the sound. Things can sound great but people still sell them off - why? Some just stick with sounds-like-Boss gear - why? It's about the
feel and with high gain pedals, the differences tend to be more apparent. For example, I think that it is ridiculously difficult to bridge the feel-requirements of heavy metal technical rhythm (djent) and a nice soulful, singing, emotive solo - with one pedal. For djent, you want it damn tight, responsive and thumping. For the solo maybe something more "tube-like", saggy and compressed.
I think the Openhaus (older version) was mind-blowing for that solo feel. The newer ones, if I recall correctly, were a lot better at rhythm with minimal compromise on the solo feel... but it's something that this bedroom wanker couldn't live with. Something like that.