As far as cleaning ability and quality, Dolphins are highly recommended and fantastic little robots. You will find many members here including myself who are very satisfied with them.
It is true that the more basic Dolphins do not come with the fine filter which is for sand and pollen and very fine debris. The filter that comes with the E10 and other similar models mainly will catch large dirt, leaves, sticks, rocks etc. It sort of depends on what type of debris you mainly get in your pool and how much of a clean freak you are. If you want every spec of dirt out, then the finer filter is going to be a required accessory. For an above ground pool, the models that are "designed" for the above ground pools are the Dolphin E10, Escape, T15, S50, or Active 10 (same model different names). None of those will come with a swivel or the ultra fine filter. If you buy the E10 or similar, you will also need to buy the ultra fine filter at an additional $65. If you want both included you would have to upgrade to the S200 or Active 20 (same model different names). This model is designed mainly for in-ground pools so it will attempt to do the walls and "waterline", so that might be an issue for you. In either case, most members here have found that the BEST deal on Maytronics Robots is to call Marina Pool, Spa, and Patio in Colorado and ask for Margaret. She can set up a telephone order for you and it will be no sales tax and free shipping to Texas for you. See what the price would be for the E10 or similar model and compare that with the S200 which will have the fine filter and swivel included. I do not believe the above ground models have the option for a swivel cable since these are supposed to be more budget friendly and basic cleaners for smaller, above ground pools.
If you want the bluetooth and remote/app capabilities, you need to upgrade to the S300 or S300i, which will be an increased cost. These models will also give you an option to do a "quick clean" cycle which means it will only do the floors and will skip the walls and water line. That might be a way for you to eliminate the issue if you have compatibility problems using an inground cleaner in an above ground pool.
