It seems there are increasing # of manufacturers nowdays using the dimond tweeter & accuton mid/bass drivers. Isophon, Marten, white Lumen to name to few. I guess for Zood, it comes down to what he is looking for in an upgrade. If you want smooth infinite extension on the top, detailed, trasparent mid, don't care much about low bottom extension, then yes, I am sure Tidal and any of those using diamond/accuton combo should be a good choice. However for the money you spend, not sure how far an upgrade you will get from Thiel. You are still stuck with bottm octave missing, your mid although very accurate,transparent, and detailed, lacking in body/weight. For the money you are about to spend, you should carefully audition # of choices you have out there.
I had Thiel 3.7 up until about two weeks ago and I was very happy with it for a while..better than any other Thiels in the past in my personal view. then I upgraded to KEF 207.2..in terms of price, I guess the proper word is exchanged..because the price difference isn't that big. KEF 207 2 deliver exactly what I wanted more from Thiel. clean bass extension below 25hz that seamlessly integrate up into mid and high area and the mid that produced more body and heft to deliver you more close to "you are there" sound. For a little money I spent, I felt it was remarkable upgrade choice..
Zood, you asked about Salon 2 in your post somewhere here, so I think you should try that as well. Salon 2 and KEF 207 2 most definitely given their price point. Salon 2 is truly remarkable as well, the big difference from KEF being the mid. less body or "bloom" as some may say..The salon 2 also extend down far so you got yourselves a true full range speaker.. I am sure there are more choices but these are two I would suggest personally from what I know..
Good luck and what a timing to purchase a new set of speakers given Christmas is right around the corner !!