Thinking of upgrading speakers from ProAc 3.8 I have enjoyed in my system for 23 years.

The new ProAcs are very good and retain the warm, smooth and natural sound of older models.  They are very good at integrating the ribbon tweeter with the other drivers, something that cannot be said of most speakers employing ribbon tweeters.  I don’t know about durability, but, it should not be hard to replace a tweeter if it did blow.  These days, that kind of failure is not that common unless the speakers are pushed really hard.

proacs remain among the very finest dynamic speakers out there, imo

they magically balance the contrary notions of see-through clarity and musicality, with an open, vivid yet still warm and human presentation - they have always sounded just right to me (which is why i still have 4 pair in house 😂)

the ribbon tweets are easily replaced if one does something stupid and damages one

spendors, harbeths, vandys, buchardts, audio notes, spatials, focals, klipsches, kefs, totems, decwares, shun mooks, grahams, sonus fabers, dynaudios, have all come and gone over the years, but the proacs have stayed in the fold

For people familiar with D48R and 3.8, is it worth the upgrade , or do I need to go to K6 for it to be worth it. 

I wonder what their future will be. Stuart Tyler was brilliant at designing as well as voicing speakers.