Should I upgrade my Tubes

I have a Rogue Audio Magnum II which is 100 Watts per channel paired with Vandersteen Treo CT speakers. My tubes seem to be shot as suddenly I get no amplification (just very low level audio). The 4 power tubes are TUNG-SOL KT120. I have been reading about getting "better" tubes but every discussion seems to get into "depends how you like the sound" types of comments similar to every other audio component - LOL.

So what's a man do ?