If it’s a short stay, one to three nights, then the Marriott makes good sense because the location is good to see a lot of the city quickly and if nothing else you get the stunning view across the river to the Castle. Longer stays I would move a bit deeper into Pest to be close more "real" along with the tourism.
The Hilton? Well, I think everyone should stay in Buda once. Possibly on their 4th or 5th trip. It’s just so far removed and so isolated from 90% of what people go to Budapest for. And, right now, the Buda Castle district where the hotel is located is under construction. It’s a mess up there. Fisherman’s Bastion is fine, and the immediate Castle area is Fine but the rest of the hilltop is a mess. Then there is the 20-minute bus ride (or 30 to 45 min walk) to Pest every time you want to see something or go for a good meal. And the walk, well it pretty vertical.
Unless you are married to the two for preference or because of discounts that you get, there are a lot of great hotels in town. Look through some of the old posts.