I have a 16 lb 29 inch tall 13 month old who is currently cruising but not walking and she LOVED this. Like, did not want to get out and once out requested to get back in. I was forced to walk her up and down the hallway, which was not quite how I saw this working out. But I found it pretty comfy!
You can adjust the position of the lumbar bar (the screws don't screw; they are spring-loaded so you just pull them out and slide the bar up - the little rubber fillers in the empty holes can be moved to the vacant holes) and also the strap length. Baby can easily reach the bar with her feet on the highest setting and with straps adjusted for me (height 5'5" but long torso). I was surprised at how well the bar worked without the optional belt but for a longer time I did appreciate the belt. Did not find the chest clip particularly helpful so I just left it. Very easy to get her in and out of even on my own and to adjust straps. Even without a high surface, I could lift it and her just like a backpack as long as she was clipped into the seat (I also personally would be fine with her being in it without the safety straps). No issues adjusting the placement of the kick stand while wearing it.
Feedback for the next edition: I do find that if you truly put the lumbar support bar where your lumbar support spot is (like where I'd put a lumbar support pillow), then the poles do kind of dig into your rear because the lumbar spot and your butt is curved and the poles are not. I feel like maybe if the poles were farther apart that might be less of an issue (but then I guess it would depend how wide of a body the wearer has). I guess maybe I'm not 100% sure where exactly the lumbar bar is meant to hit, but it still works and is pretty comfy even if it's positioned lower. Agree with needing the cover to be washable or at least a more practical color than white (!!) and if there is some way to configure a removable UPF50+ sun shade, that would be a great accessory. Optional belt needs to hook into the pack more securely (did have it slip out once) but it's not a huge problem. Would love a built in hook or something to be able to hang it on the wall easily. Baby's legs are not in M position, which I guess can be okay for toddlers, but it does seem like the seat design could easily be altered to adjust this (like just make it wider at the crotch? and/or add some structured padding at the leg openings a la ergobaby carriers?) I also wish the lumbar support bar were more intentionally designed in terms of shape to also serve as a foot rest for baby. All in all, though, there's nothing else like this on the market and I feel it will grow with my kiddo and be uniquely helpful. I hate getting in and out of the soft carriers and this solves that.