I have every combination of pure tungsten, lanthanated, ceriated, and thorriated rods. I suck too bad at tig welding and can't tell much of a difference. I normally just run pure tungsten.

But in all honesty the only reason I have thoriated rods at all is because I was messing around with some homemade geiger counters a few years ago and wanted something to test them with. Too bad I'm dumb and the alpha emitting thorium don't cause many counts on geiger tubes that are only sensitive to beta and gamma.