I spoke to Simon about the argon road bike and came to the conclusion that it wasn’t a very good bike. Not because it was stiff, but because the geometry is all wrong. The argon 18 is going to be stiff, though I have ridden one and was comfy enough, an more important was stiff enough for me. I’m not your average biker!
Having said all that, I did ride across Africa on my nicolai Mtb, that was quite stiff too but my back survived. I’ll happily ride that all day. Last week we did from forking to Brighton off road and was perfectly comfy!