Exactly...the AE stuff definitely has its own sound to it. Like I noted before, there's definitely some of that old EML "grit" there. But there's no need to house any of it in a Mantis...AE has six different cases already, Euro adapter modules notwithstanding.
It's also worth noting that you can't necessarily patch a Eurorack module directly to an AE one. The AE system is rather different...it doesn't want to see negative CV values, and all CVs must be between 0 - +5V. Most Eurorack modules, however, can deal with up to 10V bidirectional. In order to interconnect these, you'd have to either...
1) attenuate the voltage levels AND establish a common groundplane for both systems, or...
2) use an adapter device. AE has the 4I/O, Soundmachines makes the Nanobridge (I use both, depending on what I'm trying to do). These correct voltage levels AND polarizations, with the Nanobridge making use of the AE's bus +5V and ground as references.