I'm an in-house tech and I use Molloplast-B for permanent soft-liners, and we used to use Permasoft as semi-permanent, chair-side for refining immediate dentures after about 6 weeks until the 6 month reline, transitional dentures for Hader bar implant cases and such. For some reason the Dr insisted on switching to Coe-soft for chair-side work. My experience has been Perma-soft is "soft" for 6 months, Coe-soft about 3 weeks, but she's the one with the license and pays the bills.
The reason for choosing Molloplast-B over Novus is purely financial, If I was busier I'd go with Novus as it processes and finishes much faster.