Hilton Grand Vacations is a much more up-scale, resort-y type property while the Springhill Suites is very much a standard hotel.
The rooms at HGV will offer a separate bedroom and washer/dryer. The Springhill rooms will have a partial partition (half-wall) separating the living and sleeping areas but no separate bedroom.
The HGV does not provide a complimentary breakfast with your room rate, but the Springhill Suites does. The HGV will have a small kitchen in the room where the SS will not.
IIRC, the SS shares the pool area with the adjacent Fairfield Inn & Suites. It is themed for SeaWorld with a little kids play area. The HGV pool has a waterfall and is much larger and elaborate than the SS hotel pool.
Both have free parking and offer all the great perks of onsite SeaWorld hotels (free Quick Queue, free transportation to the parks, very close to the SW parks, etc.).
Hope that helps! Only you can decide what is ultimately best for your family
. For me, if I had to make the same decision....HGV hands down
. Lovely property and larger rooms with a separate bedroom, kitchen and laundry facilities.
