To those who have had both the LR3 & the LR4, what do you prefer over the other?

I've had my LR3 since 2018 and that baby is still going strong. It's gotten new pinch sensors and a couple other quick fixes here and there, but I love that it's so easy to work on.

I've seen people complain about whatever kinks the LR4 may have. Is it worth it for the upgrade? I love the idea of the litter hopper too!

As far as it goes for look, noise & space, those aren't deal breakers for me. Something quieter would be nice but I'm mostly worried about a machine that works best for my kitties!