The Park Tower Hotel is part of the Sheraton BA property and they share amenities including health & fitness club. There are separate lobbies, but are both accessible with provides for an expanded selection of bars, restaurant, and amenity options.
The best part about staying at the Park Tower is the customer service - from the front desk, bell stewards, waiters, gym staff, and concierge - they all go out of their way to ensure you the best possible stay, and remember your name. I enjoyed breakfast and dinner at the St Regis Restaurant on the 2nd floor and room service, with provides options from the 4 various restaurants.
My room was on the 10th floor with an amazing view over La Torre (Inglaises/The English Tower) and Retiro, on the opposite side, views are over Plaza San Martin. You will have an excellent view on either side. The rooms are spacious, and if you reserve a corner Junior Suite, it's huge! The furnishings are classic, well maintained, and very comfortable. There is a nice seating area, desk/work area, and comfortable bed with very nice bed linen. I love the bathrooms - marble counters, with brass fixtures, soaking tub in addition to walk-in shower, toilet and bidet in a separate WC. The towels they provide and of good quality and they are very generous.
This is a large property that's been around since the 1980s, and there are some maintenance issues; however, my overall impression is that they are making an effort to maintain and update the hotel(s).