None of our amps use 5ar4's anymore(haven't for 5 years) so I haven't picked one up in years. I am now working on one that I need to replace, so I am looking for input. I used to use the Chinese (One electon?) 5ar4's and they seemed to be the most robust of the new tubes years ago. Is that still the choice or has someone else come out with a better one? Thanks in advance.