Paradigm Studio sub 15 vs Paradigm signature sub 25

Recently I purchased the 4k bluray version of Godzilla vs Kong. Absolutely the very best movie I have ever watched in terms of low sub bass sound effects. Many reviews rave over the low frequency effects of the movie U581. Frankly speaking, godzilla/kong takes the cake here and it's not even close!

Anyways.. the question I'm seeking answers to is this: how much better is the Paradigm sub 25 than the Paradigm sub 15? I've been on the lookout for the sub 25 to either compliment or replace the already extremely impressive sub 15. A few reviews have mentioned the 25 is more tactful, agile, and deeper than the 15. Im just wondering if it's worth the time, effort, and money to jump on the next opportunity to buy a sub 25. Thoughts anyone? Thanks!
I haven't heard that sub but I do own several sets of Paradigm speakers and they sound very, very good.   Their performance is way beyond their retail price, so if you can spring for the bucks, I'd just buy a 25 and determine for yourself.   Odds are, you will be happy with it.   

And, of course, there is nothing wrong with a 15 backed up with a 25....

I've owned a few different paradigm speakers too in fact. Studio and signature models for the fronts and center channels, but I've since moved on from them. The sub 15 I have yet tho still impresses me for theater duties. I've been keeping my eyes open for a sub 25 but haven't seen anything since I've gotten more serious about upgrading.
I actually own both those subs.  I use the same AVR in two different systems, the Anthem 520.  The rest of the speakers are different.  In one system, the fronts are small monitors and the sub handles everything below about 90; the other system has floor standers and the sub is dialed in lower, and therefore it’s hard to compare.  With that caveat, I don’t notice much difference between them.  This may also be due to the Anthem Room Correction which offers great flexibility.