I am awaiting delivery of my HT3s. They will replace my latest-generation HT2 TLs. (Inquiries welcome on the 2s.) I've heard the Soundscapes, but not the 3s. Here's what I expect, based mainly on communication with HT3 owners, Jim Salk and Dennis Murphy. The 3s will have superior base in a very audible octave. Also, the 3-way design will free up the midrange for a tad more clarity. As I understand it, the 3s have the same woofer as in the Soundcape 10. Obviously, they don't have the passive radiators.
I hasten to note that the HT2s are the best speakers I have ever owned. That includes Merlin VMXEs, Revel F50s, Wilson Watt Puppies, JMLab 1027 be, and several Thiels. I expect the 3s to be even better, though.