They're great sounding amps, enjoy it! If memory serves, it can take both EL34 and 6L6 power tubes. I don't recall if it will take other octal power tubes, it might.
They're mostly hand-wired, and very transparent until the gain kicks in. They respond quite well to NOS tubes, if you're into really tweaking the thing. I find that replacing the power tubes periodically prevents problems and keeps the thing sounding great. I use NOS power and preamp tubes, and they last a long time in my studio, but that's going to depend entirely on how often, and for how long, you use the tubes and can't be predicted accurately (i.e., no one can say if power tubes should be replaced every six months, once a year, once in a blue moon, etc.

). Good preamp tubes last forever, so no worries there. If you can find some NOS RCAs, Sylvanias, GEs, etc., you'll probably find them a very good investment with that amp.
In general, with the singe-channel PRS amps, having the Master volume up at a healthy level is the best way to get the most out of the amp, using the gain to tweak to taste, and from there, using the guitar's volume control to clean up, or dirty up, the signal.
I usually set my PRS amps up with the guitar volume around 5-6 to get a very light crunch. Turn the guitar volume louder for more gain, turn the guitar volume down for less, and start with the tone control in a place where you can use it to enhance or decrease the high end as well.
If you start with everything on the guitar all the way up, obviously you have no way to increase gain, volume or brightness when that's called for, unless you use pedals, so I do it old school as I've described.
Obviously, it's a good idea to understand how to bias the amp for whatever tubes you're using.
I find that the PRS amps, like most single-channel vintage types, are excellent pedal platforms, so don't be afraid to run the amp at a lower gain setting than you might ordinarily, and push the front end with boost or overdrives as needed.