I think it depends on what you want to do. If you want to do C-L work or geriatrics, then you probably want to get exposed to as much medicine as possible (and there, ICU experience IS helpful). If you want to do all pyschotherapy, it's less important.
You definitely want to feel comfortable with medicine, because you will want to be able to advocate for your patients who may not be getting the medical care they need and deserve because they are "psych patients" (as viewed by many people in the medical establishment). In addition, you also will want to feel comfortable enough to make sure you can determine when you should be worried about an underlying medical illness in the differential diagnosis of your patients.
A broad range of exposure is what is most helpful (doesn't do you much good to spend all your time on the cancer ward and be clueless about CHF, DM, etc.) Personally, I wish that I had more outpatient medicine exposure (all my time was inpatient on the wards).