Hilton vs. Vista
Hi,
My 2 cents - You're right that the rooms are a bit nicer/more modern, and they're the highest floors in the hotel, but the size is the same, and all rooms have balconies with a view. The Vista lounge is enormous and has the best views in the hotel by far. The Executive Lounge is small, but it has everything you need, including wine and beer, and the food is great. The Vista has even more options, and room for you to spend time there. I would advise you don't base the decision on the room, but rather whether or not you're going to use the lounge that much. Note that the Hilton EL does not allow children under 16, I think the Vista lounge does (if you're traveling with children I would confirm directly with the hotel). I don't remember seeing any benefits for Vista at the pool or beach.
For personal travel, I stay at the Hilton on points (70k points with a 5th night free, I've never had problems finding available 'standard' rooms but I book very early), and forego the Vista, which they charge more than double the rate for.
If you're paying $ and can make really good use of the Vista Lounge, go for it.
FYI - You can ask for a north-facing room which has views of the Tel Aviv port area, or a south-facing room which has views of Jaffa.