Terminal 3 is my jam these days. Flying primarily United from Denver, this is where I get in and out of Las Vegas.
Never too crowded but definitely not a tiny, regional airport vibe either. Th tes just enough food, drink, shopping and gambling options to feel like you're in Sin City.
Upon arrival, I usually don't stop in the terminal. It's "go time" straight to car rental or Uber pickup in the parking garage. However upon return home, I like to grab a bite to eat while waiting at the gate. A bagel or Aunt Annie pretzel does OK. This most recent visit I had a CPK salad. Not the best but it did the job.
Of course there's slot machines by the gate to pass the time. Not my cup of tea, but that leaves more opportunities for other people to lose their money before heading out of town
Flights are generally on time, if there is a delay it's usually the destination city or a passenger who overslept - the sheer amount of traffic from McCarran necessitates a strict adherence to schedules.
The addition of T3 helps solidify that Vegas is growing and growing each year. It's a big airport and gets tourists in and out like a pro.