I am wanting to see if I notice anything as far as behavior, of course it's only day 2, they seem calm and happy.
My thought on a heat pad is the chicks don't always make a correct decision about staying warm, especially the first week, as shown by the chick who got out from under the mom and almost died from it.
The heat lamp allows me to decide what is best. I'm a control freak sometimes and the heat plates remove that type of control. I hadn't been aware of the idea that folks thought that is was bad to use a heat lamp, so now that I am, I'm paying attention more to see if I see anything. I've always used a heat lamp, I use a 125 watt bulb which is less intense than the usual 250.
I like knowing my chicks are the temperature I want them to be. I can warm up a chilled chick, but a heat plate requires a chick to do it itself.