Overall, the Adidas Ultraboosts are supportive running shoes that will provide your feet with comfort and stability, but plenty of flexibility and movement. This translates to more freedom for your feet. You will not feel like the shoes are super stiff or not giving you enough room to run, change direction, and have a good range of mobility. I think one of the main difference between the shoes as far as functionality is concerned is that the Adidas Ultraboosts provide more cushion for your foot upon foot strike, because they were made with running in mind. The Adidas Ultraboosts Uncaged can definitely fit into an active style but they are marketed to consumers more as a light activity, casual shoe that you can definitely stylishly rock with jeans when you are out in public, looking "athleisure cool". On the flip side, though, the Adidas Ultraboosts Uncaged are much more lightweight than the original model, and so running may be easier. You mentioned you were a heavier runner, and this might make a speedier leg turn over easier for you.
From an aesthetic standpoint, both look great. They both come in a variety of colors and sizes, and so they can pair well with most of the attire you already have hanging in your closet. Both are comfortable. The Ultraboosts (regular) are comfortable in that they are supportive for running. The Uncaged are comfortable because they have a lot of cushion and softness, so (again) great for a more laid back day.
As for your question about the fitted ankle on the Ultraboosts, I think it will ultimately come down to personal preference. Consumers report, for the most part, that the fitted ankle is comfortable - but if you work out hard in them, sweat a lot, and intend to put a lot of miles on them, then it is likely you will experience some chafing if you do not wear higher socks, and the fitted band will eventually start to lose its integrity after so much sweat and wear. If you want a stable shoe that will last through a heavy training load, you are likely better off with the Adidas Ultraboosts originals.