Pathos TT

I have a chance to purchase a Pathos TT. I know it is a hybrid, but is my first venture with tubes. Any comments on this piece of equipment would be greatly appreciated. I plan to drive a pair of Tyler Acoustic Super Towers with it. What is the meaning of "a matched set of tubes"? I assumed it was two tubes of same make and model. Someone else mentioned it was a process that matched each tube at an exact something or other. So if I were to order tubes, they would need to go through this process before they are ready for the amp. Thanks in advance.