I've been playing the Keizaal modlist for Skyrim since about a couple of weeks. I'm level 29 now.
Anyway it's a pretty good modlist considering it adds literally I think Skyblivion and deepens a decent part of the mechanics, but I'm not 100% convinced. It surely doesn't feel more immersive, if anything it makes the game more "Skyrimey", which is fine since I also tried modlists that make the game so hardcore it's unenjoyable, and so I can't tell if it's Skyrim itself that leaves me wanting for more or if it's the modlist that lacks some spice.
It's a good modlist though, it does clearly improve the vanilla aspects of the game, if you want things to remain vanilla.