This is the understanding I have about the EVH line of amps, basically there are 3 variations:
1) the standard 100w (very early models, about the first 1000, came with a mix of EHX and Sovtek tubes, later models have all JJ's)
2) the 50w (only came with JJ's) with the sonic differences being more gain on channel 2 compared to the standard 100w and the addition of a resonance control. No changes in EQ voicing.
3) The new 100s. Has increased gain on channel 2 AND 3 compared to the standard 100w along with EQ voicing changes and resonance controls for all 3 channels.
I have both the 50w and 100w (one of the first 400 made w/ Sovteks and EHX tubes). I like the 100w slightly more in every aspect over the 50w. I like having less gain on channel 2, because I boost it. I like the boost gain more than the amp gain. Channel 2 (even boosted) is tighter, more organic, less compressed than channel 3. So, in essence, I have 4 channels: a clean, crunch, tight high gain (ch 2 boosted), and a "loose" high gain (channel 3).