I think, overall, Seroquel has been good to me as long as I take it at night. When manic it was increased exponentially (morning and night) and when I finally got over the mania I had to titrate it down very slowly and was meanwhile falling asleep at work. Tapering it down also tends to send me into hypomania or depression, so -at least for me- it has to be done very very carefully.

I don't know about XR, but I wouldn't take IR during the day. At night I pass out on it within 45 minutes. I take it with Abilify and Lamictal and I've been stable for a year and half aside from a month-long depression. It's a very good combination of meds for me and I think Seroquel is an essential component of it.

The side effects for me are sedation (could say extreme) and weight gain due to terrible cravings for sugary foods.