Pit wheels are a pain. You've got to take them off another bike, transport them, and then bring them back and put them back on the bike. For many of my first races I brought them and never used them, so I stopped bringing them.
Until I needed them. It was a road race that I was going strong in, that featured an uphill finish that suited me, and while I was in form.
I got a flat.
I had to stop, the wheel truck and dropped riders passed me, I took off my shoes and socks and started walking. Luckily, the race (it was the Georgia Tech Collegiate/Open RR) had great support, and one of the racers I knew in a support vehicle stopped and gave me a ride back to the start.
And I've brought Pit Wheels with me to every race since. Because you never know.
They want you to attach your race number to your wheels, but I just put my race category, team name and my name on them so I don't have to deal with it at the race. One on each wheel, on the skewer.