All of mine except Kissy were chipped when they got spayed. I would never do it to them when they were awake. It is extremely painful to insert that grain of rice. I saw a big dog get it done and it really hurt them. I can't imagine doing it to one of our little ones when they were awake.
I highly recommend it but not when they are awake. If i ever have Kissy put out for anything, i'll have her done. They didn't have it availalbe 7 years ago when i got her.