Well, I'm starting my 11th season with my Tiger Shark, but its the only robot I've ever own and have no comparative experience with any other brand. I got mine before Hayward bought out AquaVac so things may have been changed, but here's my experience
Does a good job cleaning ( i throw it in once a week during the season)
Climbs walls to the water line.
Did get caught up on my main drains, but I added drain ramps
Bottom loading filter cartridge is not a big inconvenience for me, but may be a disadvantage for others
Parts are readily available on line. (I have bought addition cartridges, filter panels, and a impeller over the years)
Never had a major failure or repair . ( it did suck up a rock once and broke the impeller)
A few years back I bought the caddie for it and found that for me it really did add any value.