We're talking here about a modded classic Skyrim difference with a modded SSE...
Without ENB, to be honest, I don't see any difference with modded classic Skyrim. With an ENB, the main difference I can notice is about shadows, fogs, smokes, ... this kind of things, since we can't really add too many of them because of 3.2Gb limit (or only with 'screenshooting' purpose in mind). I use Vivid ENB in classic Skyrim, so maybe I'll change for the Truth ENB, to see if those effects are better with this one while not hindering fps vs. Vivid, which I don't know. If the Truth ENB exist for classic, which I've to check.
If I change to SSE, it'll only be because of 3.2Gb limit reasons. It would then offer me an absolutely enhanced gameplay (if I can mod it correctly while avoiding conflicts) and some negligeable, if any, graphic enhancement as well. I definitely won't change because of better graphics, really. There's no real difference, in my opinion.
I forgot to send you the screens :)