Never take advice from fanatics or Dr.s who would presume to tell you that you wouldn't understand something that's very easy to understand. Spec's as text do not matter but Stereophiles graphs mean a great deal and can tell you 90% of what yopu need to know about that amplifier. Especially when they can't test it near it rated power etc...read between the lines to get the truth.
This question cannot be answered without knowing what speakers you are using. Tube magic is not available to all people! some speakers just will not work well with tubes. Most of the speakers I like are in this category. So what speaker do you have? is a huge missing component to anyone answering these questions for you.
Personal Anecdote.
In my world where the drivers in my speakers are highly damped, have moderate sensitiviy and very flat phase responses. Most tube amplifiers are at best tolerable. They are usually flawed and ill equipped to to do the job I require. For example, Wolcott Monoblocks vs. Warner Imaging Monos on Kharma Exquisite midi's... Tubes distortion is obvious in the boom in the bass and glare in the upper mids. About the only thing that could be enticing to a listener is the overblown diffused soundstage the tubes give you.
This is just one of many examples I can give, tubes in a multi channel application are a proverbial root canal causing more probelems that they solve and will do nothing to enhance your two channel performance. Most good multi channel preamps give you the flexibility to change the sound so dramatically you can make your system sound like its on tubes. The average audiophlie will moe likely hang his speaker wire on wood bridges to make the system better before they will grasp that multi channel which REQUIRES you buy competent speakers and have an excellent processor eqippped with the propper setup parameters and understand some basic acoustics to dial in your speakers so they work as one.
Subjectivity in sound is a much narrower window in multi-channel and you can't make equipment work that doesn't. Its a binary world (1) it works (0) it doesn't. So you can see how that might make analog types feel trapped. Because you can't cover up ineffective equipment with tweaks and other band aids, like tube amp tone controls.
If you don't have a Meridian surround processor, then use your tube amp money to get one and make your two channel days a distant memory. I haven't heard a 2 channel system in the last 3 years that is better than my or many of the Meridian or TAG McLaren multichannel systems I have setup.
I realize that 99% of the people here have had the opposite experience, but Bose does sell 70% of the speakers in the US. So the majority isn't always right.
I will say this, I have not yet walked into someone's house where I could not improve their multi-channel sound significantly (I work in the industry and this list includes some very noteworthy people) just by adjusting the setup on the equipment they had. Most people are at best getting 50%-60% of the performance out of their MC systems. Keep in mind too, some speaker co's still can't make a center channel and most audio stores won't sell you three of a kind for the front speakers etc. Lots of wrong approaches to the whole multi-channel thing. No wonder people fall back into old bad habits.
Have a good one.
If you have more question or need technical backup let me know.