I went on Lamictal 2 years ago after being on Depakote for years. Once I got to 100 mg., I felt great!!!! The only side-effects I've experienced were a bit of a rash the first week that went away--thankfully, and muscle twitches that I still get when I'm going to sleep. I don't know if it affects my sleep--I have Fibromyalgia so every does!!! A couple of great things about Lamictal is an enhanced sense of well-being, and reduced appetite.
One thing I love about Lamictal is that even when I become hypomanic [have BP2], my mind isn't racing nearly as much as on other meds.
If you have any side-effects, contact your doctor--especially a rash.