Sometimes they can be a bit loopy, and lack depth, and sometimes they can be fairly "deep"
Does it matter?
Hydraulix is good, professionally executed solid up-tempo party techno with a dose of `avin-it-ness.
If you want detroit, get a detroit record. If you want schranze get a schnranze record.
Your mate sounds confused.
Does she expect some 6/8 deep experimental audio experiment on hydraulix or somthing?