I'm a little iffy on the taxis. They had us go in a Prius with 3 adults and 4 checked pieces of luggage. It was a tight squeeze because one of the suitcases had to go in the front so all three adults were in the back (we all fit fine, but it just wasn't that comfortable/not ideal). They seem to want to have you go in the next taxi in line, and because the vans were 3 and 5 cars back we didn't get to take them. Maybe we should have went up and requested it? We just went where both organizers directed us. We normally have a decent experience with taxis, just not if we're traveling with luggage and 3-4 people. We were also charged $60.00 flat (excluding tip, $70.00 with it) with no traffic from SNA to Desert Inn. I think the pricing might have been wrong on that but I didn't push it. The meter wasn't turned on so that was a little...strange.
The Uber XL was fine on space and arrived quickly (5 minutes from the time we requested to her being at the hotel for the return), but she was a bit of a wild driver and had several cars she cut off in traffic that honked with one cutting her back off from the HOV lane. We watch the Road Wars show on A&E and I was sure we were going to be on there next.
Your experience might be different than ours, but it's given me pause on what transportation to use when we get to the airport. We've used Primetime several times in the past and have had a decent experience. Lansky also gets really good reviews here and their SUVs look great (saw them when they were picking up at the GCH).
I wish SuperShuttle was still a thing. We had great luck with them always being reliable.