Paul and Aaron, thank you!
Room, system and personal preference really do play a major factor in how we perceive any component. Example, I know many people really like the 45, but it's too "modern sounding" for me. I prefer the 2A3, 46 and of course the 300B (at least in the amps I have heard).
Given the above, when Paul describes the SIT-2 as "...like a 45 SET but with 10W, and even more extension on both ends.", it's probably not for me. Also, Aaron makes a good point about value. Those SIT amps are not inexpensive. The only thing question left is, how would a pair of SIT-1 monos sound? Of course they are double the cost!
Gerry