Definitely helps with the Diabolik to run a passive bass direct in, then the clean tone sounds really dark and bassy. Flick to active, or put any buffered pedal in front, and the clean tone sounds thinner and full range.
I’ve not used the Amptweaker either, but seems more versatile, perhaps a bit more utilitarian / vanilla / boring. Whereas the Diabolik might be more limited but it has an incredible sound that you might struggle to replicate and it’s more likely to generate bass face.