My thoughts for each race.

Between the two, which race should you consider for F1?
Vibes

Austin: The race at COTA gave a true fan feel. It felt more down to earth and offered a festival vibe—regardless of what ticket you have, you are free to roam the entire grounds.
We had main grandstand tickets, but walked over to the general admission area right next to the track to watch the driver’s parade and see the drivers up close.
We sat at Turn 12, Row 24 and it was great! Got to see overtakes and most of the track. I recommend sitting high up if possible since it allows for more views. Note that the bleachers are metal and will burn your booty — we brought stadium seat cushions with backrests as they were highly portable!
Las Vegas: The atmosphere felt more lux. You are confined to the section you hold a ticket to, which made it feel more exclusive considering the huge difference in prices. Entertainment was offered at the higher-priced sections.
We sat at the Silver Main Grandstands, Section 102, Row 12 and got to see the cars slow down for Turn 1, the pit lane exit, and the jumbotron. I actually prefer and recommend the lower row seating here since it’s a street circuit and it isn’t possible to see very far or other parts of the track. Plus, I imagine much of the lights and structures to affect visibility from higher up top. Note that the seating here (at least in the main grandstands) are actual seats with backrests.
Prices
Austin’s lower prices are highly favorable all the way.
We paid 300% more for our Las Vegas grandstand tickets than at COTA. Was it worth it? It was nice to experience this race for the first time since its inauguration three years ago.
However, I imagine we will want to spend that same amount of money and travel out of the country for a different race in the future.
Added costs is the premium for other expenses like food and lodging. Everything was more expensive in Las Vegas.
Accommodations
Austin: Our hotel was about 12 miles from COTA. I found it highly convenient to drive to and from the race. We drove all the way to the event center and parked in a field directly across from it for $50. This was cheaper than the official lots. The location also lessened the amount of walking to and from the race, which was a godsend afterwards since we’d have walked a ton already.
Las Vegas: Our hotel was a 15 minute walk to the event entrance. I recommend booking a hotel on the strip that’s within close proximity to the designated entrance for your ticket type! There are many road closures and your path will be rerouted; use the F1 app to map out your directions because a regular GPS app will send you around in circles as it doesn’t account for the road closures.
Weather
Austin: It was ridiculously scorching hot at this daytime race. I had an umbrella with me the whole day and could not imagine getting through the day without it. Make sure you apply and reapply sunscreen throughout the day and wear a hat for protection! Drink plenty of water to rehydrate as well.
Las Vegas: It was pleasant during the day as we perused the strip, but by the time the race started late evening, it got cold. Luckily it didn’t rain race day, but it had rained during qualifying the previous night.
Speaking of which, we missed qualifying since our flight was delayed. . . by nearly nine hours!

Considering this November race is around the holiday traveling season, bad weather and flight delays could adversely affect your trip plans like it did ours. We were just glad we finally made it to Vegas for race day.
Race Commentators

Whenever at a race, do yourself a favor and swing by the Amex booth to grab a radio! Otherwise, you will sit there not really knowing what’s going on during the race. If you don’t have an Amex card, bring earbuds/AirPods so you can connect to F1TV via your phone.
I heard the Vegas’ commentators at the race did a piss job, so be prepared and give yourself options.
If you don’t care to know what’s happening, I suggest wearing hearing protection earbuds because it gets really loud.
Peep that guy’s F1 x Hello Kitty collab track jacket. It’s dope.
After getting to experience both races, if I had to choose between attending COTA or LV’s street circuit, I would choose the Austin race. The prices are way more reasonable, there are other activities you can do around the city, and have an opportunity to spend your time exploring more outside of the race.
Additionally, everyone got to walk the COTA track after the race was over! Depending on where your seating was, if you were fast enough, you could catch the podium celebration. We were 12 turns away from the starting line so we didn’t make it. In hindsight, it might be advantageous to start heading over around the second to final lap.

Note that a podium is set up directly across from Section 108 in the Silver Main Grandstands after the race in Vegas. We didn’t get to walk the circuit here.
Outside of the race, I felt restricted to the LV Strip. JT and I don’t drink alcohol or gamble so Vegas isn’t really our ideal environment to be in. We went strictly for the F1 event and also booked tickets to see Shin Lim the day after, but his show was canceled. Nothing was really offered last minute for us to do.
If you plan to bring kids, I strongly recommend the Austin race for that reason alone.
PS. If you’re looking to buy F1 merchandise from Vegas but don’t need it for the race, wait until you arrive at the airport after the race is over. We stood in a long line and made our purchase at The Venetian F1 Hub, and later found merch at 30% off at the airport kiosk.
Have fun and enjoy the smell of rubber on the track!