The 370TX would be nice with the 4/4 Spiro Mittel, a bit less tension than the Spiro 4/4 Mittel high C, I think, but not much.
I never played the regular 4-string-set of the 370TX or 380TX (the only one I tried was the 380M), but the 370 has thinner lower strings (because of the higher mass per volume of the wolfram used) than the 380TX which might result in a more brilliant sound. The 380TX are more traditionally chome-nickel wound strings. For me the 370M G (which I ordered for trying) was too brilliant, but I didn't test it for a longer time.
What I don't like is the decreasing tension towards the lower strings with the 380M set. Have a look at the Corelli/Savarez website, I think they have published the tension of the E to G strings of their sets (but not the high C tensions). The absolute minimum for my taste is equal tension for all strings, a bit more tension on the lower strings than on the higher ones is better, G to E like 100% to 110% tension is optimal for me (like with orchestral Spiros Mittel or Weich).
4 year old Spiro Mittel are great. Much better to bow than in the beginning and might last several years. The downside is, that you only can find out weather you have 3/4 or a 4/4 string by measuring the uncut (!) total string length (and tell me which string it is, since they all have different lengths). I have sets of both 3/4 (unly the G uncut, but still have the cut ends of the set used on my EUB) and 4/4, so I can compare and tell you which set you got.
I still have a set of 25 year old Spiro Mittel 4/4 and I only changed them because I couldn't hold the tension after several years of not playing at all. I would never give them away (exept if they will break), because they are so nice to bow now compared to the first year, when I got them. (OK, there are still better bowable strings on the market, but none of them lasts as long as the Spiros.)