Mastersound Evo 845 or Line Magnetic 219ia

I never listened to the Evo, but I can tell you about the Line Magnetic; not only the LM219, but also the LM518 and the LM508. All of them sound amazing! The 219 is the best, presenting a wider, bigger soundstage together with more clarity and presence.  It's almost like having the musicians in your room.
The 518 is not so detailed but is more dynamic and punchy.
And the 508 is a powerful beast, able to drive any speaker with its 48W of pure SET power. Not sounding so refined and "full bodied" as the 219, but with great bass and detail.
As for the build quality and parts used, they are top notch! Kind of an industrial looks but with superb details.
I'm planning to buy one of these soon, maybe the 518. Need to audition them again.

Facten,
I listened to the 219ia for four times so far. In two occasions it was using the stock valves and in other two auditions it was running valves from Genalex and from FullMusic. And yes, there was a difference with the latter setup for the better.
As for the 518ia, I listened to that amplifier for 3 times and was always running the stock valves - which impressed me a lot! I have to trust you about swapping for better ones, it must go to another level!