Sylvania vs RCA

[timm]

Hi all. I am looking at replacing two of my Chinese tubes in my Cary slp98p. I am looking at the 6sn7 sylvania bad boy and multiple RCA - black base and either white or red letter. Anyone have an opinion or give me a description of their character ? Both are between 85 and 115 for the pair - platinum grade. Thanks in advance. Tim