Changing coil-on plug boots

I am changing the spark plugs and wires on my bone stock 2004 Prerunner 3.4L V6 which has 235k on it. I have never changed the coil-on plug boots. What is everyone's opinion on changing them out? Since they are a little pricey, should they be changed as preventive maintenance, or just wait until they go bad? What brand is best when I do change them out? Thanks for your responses.

 

I agree with Mr. Lobster. Unless they get hard or start to split.......no reason to replace.

 

I would personally pick up a spare and have it ready for when one does go bad. That way once you start encountering issues, you won't have to wait for one to get shipped to you.