At 200mg, I just take it all at once. When I was on 400mg, I HAD to split it (or my vision would get all wonky, etc.). People have different reactions to it energy-wise. Almost seems to run half and half from reading over the years. (Or maybe thirds -- energy up, sedating or no noticeable effect on energy.)

I'd have to say though that if you find it sedating, it almost seems that taking it all at night would be best. I'm curious to know what your provider says about why she recommends splitting it, mossanimal. Can you let us know what she says? (Or maybe from your feedback of it having such noticeable energy effect on you would override the thinking behind it. Dunno. Curious.)