I'll have to admit that prior to my valve surgery, I was more afraid of the cath than of the surgery itself. I had no choice of method - they used the femoral artery, and I just didn't know what to expect. As it turned out, they gave me just enough "happy juice" so that I was barely awake, often asleep. I drifted in and out of consciousness, and each time I started to look around, they said "Time for more juice" and out I went. The only really weird experience of the whole event was that when they made the initial puncture to insert the tube, while I felt absolutely nothing, my leg muscles tensed up abruptly, causing me to "jump" up on the table. Doc said it was totally natural.
Since my cath was through the femoral artery, I had to lay in bed for a while. They used some new sort of plug for the wound, so I only had to stay in bed for about 4 hours. During that time I was gradually getting more clear-headed and actually had lunch (the standard dry turkey sandwich, though). By the end of my 4-hour wait, I was ready for the ride home. The next day, I was up and around, and the day after that I was back to work. They didn't want me driving for 24 hours after the procedure, due to anesthetic.
So, for me, the cath was a big non-issue. Hope yours is, too.