*laugh* Okay, so apparently I'm not an 'informed person'. Interesting!
Okay, I don't see Spirit, Life, UltraFoco, Foco, Zona, Thron......none of those tubes are in that reference that you cite. These are the modern Columbus tubesets I know of and use for TIG welding. Nivachrom is a Zona level tube, on your list there is no thermophillic or air hardening 'Thermacrom' steels such as Foco. The HJ list is what he sells and I've used some TT tubes on some frames, including my own Tephra which is my first go using OX Platinum. I weight 205 so I expect it to fold under me any second now *laugh* ( According to the HJ website ). Come on man! If you're going to post web references, you can do better than that!
Anyway, it might be better to have a discussion on the different types of steels and what parameters dictate tubing selection? Seeing we both pretend to be 'informed intelligent purveyors' of all things steely? Okay okay, you can pretend, I'll provide the dancing monkeys.