Part of that is because the Evo is centered around the midrange and upper midrange. Those frequencies are always present in the guitar sound, loud or soft. If you play softly, the signal is mostly mids. If you pick real hard you increase highs and lows dramatically, as well as overall volume, but the Evo doesn't focus on highs and lows. In contrast, the Steve's Special is a "highs and lows" pickup, and I'm sure people will agree with me that it's a very dynamic pickup. Stratty single coils are also very dynamic for the same reason-they have a lot of presence in the high end.
Another thing that can squash dynamics is overwinding a coil. The Evo's aren't terribly overwound, but they are overwound indeed. I think your observation is correct. If it's something that bothered you, and you wanted a quick fix, you could install a coil cut, and try it as a single coil for some things, when dynamics was an issue. But I'd recommend making sure it's the coil closest to the neck (same one that should turn on in the #4 position)
Though the pickup sounds amazing, I have difficulty squeezing subtlety out of it. (I have a sucky rig, so that could be part of it)
I actually chose a PAF Pro (bridge) over the Evo, and will probably try a Fred soon.