I have now had 1 batch of chicks under a heat lamp and 1 batch under this exact plate. It was a pretty big game changer, and I will never go back.
The cost savings of the heat lamp is easily negated by the power it consumes. I think I paid $20 for lamp and bulb and then another $20 for a month of extra electricity to run it constantly. This compared to the peace of mind of the $40 plate.
Another benefit seemed to be that the chicks had a "safe place" that they could go at any time, and were just generally less skittish. With my first batch I spent many, many hours trying to tame the always-scared chicks. The second batch never seemed to develop the phobia, possibly relating to the hiding spot.
Lastly, the red cast of the lamp was hard on my eyes and took terrible photos. I'm converted.
The heat plate doesn't feel that hot to touch but it did work and I see that others had the same initial concern.