I always laugh at a title that claims to be a complete owner's manual. And I have not seen a copy of CSAORS so have not done a side by side comparison. However, Bartlett is a long-time, experienced herper. And I've seen enough of his stuff to expect a competent product. I'd expect differences in emphasis between the books, and The Corn Snake Manual is more tightly focused. But I do not think you wasted your money.
Everything I have read and my own experience says that most, if not all, snakes (including corns) do not need UV light for health. I have used a full visible spectrum light to establish a photoperiod to breed my corns. But in most cases the bulb has been outside the cage shining through the glass. (Glass filters out the UV). I did this because the room the snakes were in had only one small window. A room well lighted by the sun would not need an extra light source.
IMHO, corn snakes need access to a temperature in the mid-80s F during the day. I'm not too concerned about the how of doing it, as long as the final result is right. Certainly a UTH will do the job, though it may need a thermostat or rheostat to avoid too much heat.
Paul Hollander