definitely enjoying tree tag more with 4 v 8. in general, i noticed that the thor's win rate is much higher than when it was just 3 v 9. less people quitting when getting thor as a last entry into the game too, although those unaware of the new 4 v 8 change would still quit while the game is loading from the lobby.
the game is still very winnable for probes, especially if u get noob thors. of course, when u have experienced thors playing, the game can be pretty short. but overall, i think the change has resulted in both thors and probes having more fun. as a probe, nothing was more boring than having to wait out 30 minutes of not having to do anything and win. as thor, it was frustrating searching for probes when u have inexperienced partners.
all in all, i think it's win-win: if thors are good, the game ends fast, and probes can quickly move on to the next challenge. if probes win, it's definitely more satisfying, and not just a meaningless 30 minutes of pylon farming and massing units.