i've had some experience with both skimmers......our pool is rectangular, 50' x 18' gunite with coping around the edge, and stairs on the side. Here's what I've seen:
Ariel #1 purchased when new pool opened late July, 2021. It worked like a charm, ran until we closed the pool down early October 2021. Upon startup May 2022, it ran until roughly mid-June, then it would only run in direct sunlight. As soon as a cloud showed up or no direct sun, the paddles couldn't decide which way to go. Solar Breeze felt the circuit board got wet, they replaced it under warranty, no problem.
Ariel #2 received and started up on June 20, 2022. Worked fine until roughly mid-August, at which point it started doing some strange things with the wheel rotations....changing direction in middle of the pool, etc. By early September, it was totally dead. After contact with Solar Breeze, they gave me a deal to purchase another, and offered a decent price on a one year warranty.
Ariel #3 received late September 2022, we didn't use it until we started the pool in early May 2023. It worked roughly two months and then started going in circles, the paddles couldn't decide which way to go. This unit was replaced under warranty.
Ariel #4 received last week, tried it out for an hour, it looks fine.....but we're storing it.
In the meantime, Beta SE #1 purchased late June after Ariel #3 died.....we've been using it a month, so far so good. We paid an extra I think $40 for an extended warranty.....based on experience with the Ariel.
Observations:
The Ariel sensors are located on the front edges, and our pool has cantilevered coping. The skimmer runs into the concrete coping all the time, hitting directly on the sensors. By the third unit, they gave us plastic blocks to glue onto the front to eliminate this contact, but they did't work. We immediately told Solar Breeze this, and they sent us a second pair of plastic blocks.....so we had them on both sides of each sensor, at 90 degree angles, trying to shield the sensors. This helped but didn't work perfectly.....and the unit died in a little over one month.
They sent the newest Ariel #4 with two sets of plastic blocks. Based on our previous experience, we glued the blocks on at the far end of the blocks, such that they stick out maximum amount. When we tried the skimmer with this type of block mount, it seems like it blocked the sensors from getting hit. Basically those mounts need to be maximum length from the unit, as far as you can possible glue it on the end.
None of our Ariels would work more than 3-4 hours into the night. Maybe when we got the first one it lasted overnight, for like a week??....can't remember.
The fourth Ariel is a 2023 model, and I've read claims that it's improved....we shall see, now it's our backup for when the Beta SE dies.

I asked Solar Breeze what's changed, but they haven't answered.
Both the Ariel and Beta utilize a front rotating paddle to bring debris into the basket. The paddle seems to send out a small wave in front of each device, pushing debris away from the basket. In the end, both units collect a ton of debris and keep the pool surface spotless, but this rotating paddle idea doesn't look right to me.
The Beta sensors are located away from the edges, they never hit the pool coping.
The Beta corner bumpers are two small wheels, looks like a much better idea than the solid rubber type bumper on the Ariel.....the wheels tend to help the unit turn if it hits the coping.
Neither unit has grounded on a step in our pool, our first step must be deeper.
The Beta consistently lasts the night, we wake up and it's still going strong first thing in the morning before the sun hits it.
The basket mounts are different, but honestly they're both fine, just slightly different mount idea.
Basically in the end, when they work, both units work fine in my opinion. I'm happy with either one. It's a bummer the Ariel kept failing, but I have to believe they've gotten inundated with returns and you would think they would fix the issue. For now, we'll keep the Beta going the rest of the summer, and if it dies, we'll switch back to the 2023 version of the Ariel!