Are DR DDT strings actually stiffer?

Hey everyone, I play on a Drop C bass and I use really high gauges (currently using a 135 low string wtih 90/67/50 on top) since that's what I'm most comfortable with when playing the fast chugs and lines my band requires. However, the sheer size of the string combined with the absence of a lot of mids and highs make me feel like this isn't quite the string I've been looking for (they also die quite fast). Since I'm mainly into that very fresh bright sound that fresh strings bring with them, I wanted to try out stainless steel options.

This is when the DR DDT strings caught my attention, they seem to be the next thing I want to try out but I'm quite unsure of how much their marketing can be trusted. They claim that they are much stiffer feeling but I'm unsure whether this claim is for picking or fretting and if it is for picking, how much the core alters the feel, since in actual tension, there presumably won't be that much of a difference.

I'm thinking of trying out the 125-45 5 string set and removing the 85. Otherwise, I'll probably go with a 135 set of coated stainless elixirs. DR DDTs are quite expensive strings so if there's any info on longetivity, I'd also love to hear them.

Thanks in advance!