I've done it both ways, and much prefer the plates or always-on heating pad. Since I keep the chicks in my bedroom for the first two to three weeks, and I'm a light sleeper, I'm VERY aware of them at night. With the lamps, believe me, they are awake all night, running around and peeping...
Lamps keep your chicks under light 24/7. If you have them inside, they will be peeping and running around all night long, which is not good for your sleep either.
Plates allow them to sleep the through the night and be more active during the day. They also teach the babies about cooping and...