I've owned both the Birdfy Original and the Rookie previously, and after using the Metal Lite for a while it's become my favorite overall, mainly because of how solid and polished it feels.
The metal construction makes it noticeably sturdier and it's easily the nicest looking of the three. The built-in solar panel is a great addition and blends in well, though I do wish it were on both sides of the roof to give more flexibility with placement.
The quick-detach design is a HUGE upgrade compared to the other feeders and makes refilling incredibly easy, which has honestly been one of the biggest quality-of-life improvements. It also holds a lot of seed (at least as much as the Original if not a bit more) and I appreciate the built-in seed guard, even if the holes seem a bit large and don't always prevent messier birds from spilling. The adjustable perch works nicely too, but I think some guidance on how to best use it would help.
Setup is just as simple as the other models, but the lack of a bottom mount (which only the Original had) limits installation options a bit. I mounted mine on the same pole as my Rookie using the included hose clamp, and while it works, I feel like two clamps would have been better given the weight, especially since only one of each size is included.
The biggest downside for me is the camera. While it's easy to remove thanks to the magnet and bracket design, it's not very secure and has already come loose once. The image style is closer to the Original with a wider, slightly distorted field of view and lower frame rate than the Rookie, which may come down to personal preference, but it feels like a step back. It also lacks infrared night vision like the Original and instead uses a visible light like the Rookie.
Overall though, I'm very happy with it; it's the best-designed feeder Birdfy has made so far, even if the camera and mounting system leave some room for improvement.