Yes, I was a little nervous but I did what my Dad told me - measure twice, cut once :) I also invested in a 4" hole cutter designed for can lights - made short work of it but when the guide bit went through the fiberglass, I went outside and cut from outside in.
It runs off the normal 15a outlet - I just have to remind DW not to run the tea kettle at the same time as it pops the circuit breaker. I added a battery backup unit for her computer (iMac) so that it doesn't cause any problems if she forgets :)