Hello all, I am preparing to install a radiant system, subfloor, staple up downstairs, and radiators and/or towel warmers upstairs. Any thoughts on which brand has a better track record would be appreciated. Thanks!

I'd shop on price points. Both are VERY high quality radiators. Since they seem to be so similar, I can't even tell the difference between the two brands. Here on the East coast I get better pricing from Myson. When I was in the West, you couldn't touch Runtal's price. Be prepared to spend a bit more time than you originally planned mounting the Euro panel rads. It can be tricky getting them solidly in place and piped in correctly.