I quite like tekkit and technic, It's really easy to use and a great way to get into running a modded server.
I started running a little tekkit server for some friends months back but after I heard about the whole forestry thing...
I was rather upset, I was under the impression that anyone making a widely distributed modpack would at least have the common decency to ask permission.
After poking around the back end of tekkit I noticed some rather stupid mistakes (mismatching item IDs and GUI IDs mostly) and essentially fuck it, I like forestry so I made my own modpack thingy for just my friends. (in the process I've seen more adfly pages than anyone should be comfortable with)
Also on the subject of EE, I quite like that mod simply because it keeps people from digging up the entire server looking for ores. Had to disable a couple items though, especially the watch of flowing time, any CASUC reactor will blow up if anyone uses that thing. (messes up redpower items)
In short, I like tekkit because of it's ease of use, hate it because of it's bugginess and dickishness. Good way to get into modded gameplay\server maintenance.