I can't complain. As an infant, they don't "know" they can throw a tantrum

As long as you feed them and let them sleep on time, it is all good. Bonus if you have a kid who sleeps in car seat or stroller. We did 2 west coast and 1 east coast trip by plane. Everything went well and when DC is 9 mts old, we are going on a big international trip. We went to big cities and national parks. Did lots of hiking. I will say we did not do as much or as fast as we used to do in pre-kid days but we were both pretty happy with our trips. Ergo/kelty is also highly recommended. Be prepared but not over-prepared where you take everything incl kitchen sink. Just tell yourself you will learn from experience and then try to relax and have a good trip.
Some may suggest you go w/o baby. For us, it was a non-starter. There is no family nearby and we can't just send the infant off to grandparents. We were apprehensive before our first trip but took the plunge. It turned out pretty good and we gained more confidence that we can handle the minor glitches. If you never do it, you will never know. If you can pay for it, buy a seat for the baby. Also, we did these trips with 2 carry-ons + 1 backpack + car-seat (bought baby a tkt) + stroller/Ergo. So plan well and just go. Enjoy!