When I hunt local I dont take one. But when I am on a trip I always take one. Too much money and time planning not to have one for me.
Matthews LX and its got its own release and its own 5 arrows with broadheads. I shoot it every year before bow season to make sure its still hitting good and then put it back in its case. All I have to do if something happens to my primary bow is open the case, grab it and go hunting.
It may not be the fastest bow for a backup but the sights are spot on, and its better than going home or trying to deal with a bow shop on a hunt where you have limited time and vacation from work.....
I prepare for the worst because I have bad luck.
I try to keep a little luck in my favor for when something bad happens. And it always does.
On another note, I know a guy from Utah who killed a bull elk with a bow he bought at Walmart after his PSE Monster blew up on him into 20 pieces the day before...he took his sights and rest off his good bow and put them on that cheap bow and then had to electrical tape his quiver on the bow...went out the next day and killed that bull at 15 yards....True story. I wish I had a picture of him with that bow and that bull.