You know, I personally prefer magic/medieval, but I finally got sick of the bugginess of AM2, and the way Battlegear 2 has terrible compatibility, and the way all of the Metallurgy ores seemed the same, so I decided to take a break and switch back to tech (which I enjoy as well). I like the idea of improving your character, and I like it as a separate idea from tech, which is improving your base (in my head). But it seems like the mods with the most potential for "improve your char" are buggy, i.e. Battlegear or AM2.
It always seems like playing with magic is like this: "Oh look, a magic modpack!" *plays with nothing except Thaumcraft*
I haven't played with Botania, but from what I've seen, I would need to append this line if I did: "Hey look, a flower - let's see what it does!" *fifteen minutes later, has found horrible exploit - or maybe even legit feature - between Botania and TC and is using it to create infinite diamonds*
... I *might* enjoy playing with magic and tech at the same time, but every pack with both seems to end up with 160 mods. You need about 100 mods to really make tech fun, and magic only adds more to the count - I've found that past 100 mods the lag starts.
As a modpack creator, I've had a lot of experience with that, although most of my desperate lag-tests happened a while ago, so mods in general might be more efficient now.