My feeling is that Warps lends itself really well to being a carrier since it’s so smooth at phase modulation. I never quite gelled with Tides as an FM carrier, but the shapes it generates seemed excellent for AM, and its multiple methods of syncing to other sources kept things interesting. (The new Tides doesn’t have Freeze to play with, but does have all that quadrature/harmonic goodness.)
A post elsewhere this morning got me thinking about modules I would keep if I had a much larger system or a sort of “reserve” – things I didn’t find myself using all the time, but might want to pull out once every 2-3 months. Both Tides and Warps would have gone on that list.