The only tube Amp Line 6 makes is one in conjunction with Bogner. It's still not a "true" tube amp, and is still modeled.
As for the Soldano they're one of the premium high gain amps along with Bogner, and Deizel, but they're slightly more affordable. They might not have all the bells, and whistles that some of the other amps have for the same price, but their tone is second to none imo for high gainers. Just ask Eric Clapton, BB King, Eddie Van Halen, Jimmy Page, Steve Vai, George Lynch, Jerry Cantrell, etc. etc. who are all known users. Just read up.