I-Drive has good access to Disney and direct connection to the Prime Outlets on Vineland. Access to I-4 is also very good for getting over to Uni. SeaWorld location is just at the edge of the busy I-Drive area - lots to do there (restaurants, shopping, minor attractions) but access to the parks can be a bit more difficult as there can be traffic backups around there at times.
I don't agree that the HGVC SeaWorld location is in a potentially difficult spot. There's easy access to Disney via the nearby I-4 interchange or to both Disney and Universal if you go under the I-4 underpass via Palm Parkway (to the left) to get to Disney and via Turkey Lake Road (to the right) to get to Universal (I don't think that there's Eastbound access to I-4 to go toward Universal from Central Florida Parkway. Palm Parkway and Turkey Lake Road are, essentially, the same road.). You needn't go anywhere near International Drive traffic to get to the parks. I think this resort is likely a little bit closer to Universal than it is to the Disney parks, but probably not by much.
And access to SeaWorld is ridiculously easy - it's across Central Florida Parkway from the resort (we've walked there from the further away Marriott's Cypress Harbour resort that's next to HGVC on Westwood Blvd). Totally different traffic story if you plan to go to restaurants or the attractions along I-Drive but you'd have to deal with that congestion regardless of where you stay.
The SeaWorld HGVC is the oldest of the three resorts but looks like it has been kept up over the years. Parc Soleil, as the PP says, is the newest of the three. We haven't stayed there but the pictures make the villas looks pretty nice. This is a great central location for access to all three of the major Orlando theme parks centered roughly half way between the center of Disney and the Universal parks.
Personally, I don't like the location of the International Drive resort that's next to the Premium Outlets - it just seems a bit less of a resort location to me than its sister HGVCs. And, while Vineland Ave. connects I-Drive to the Lake Buena Vista area, the opposite end of Vineland Ave. which empties onto SR 535 can present a traffic challenge at certain times of the day - when staying in that area we usually just go down I-Drive and then take World Center Drive/Epcot Center Drive to the Disney parks. But everybody has their own preferences so that location might work for you.
The location advantages of one of these resorts over the others, in my opinion, is negligible. It's about three miles from the I-Drive location to the SeaWorld location and about two miles from the SeaWorld location to Parc Soleil.
My two cents - if Parc Soleil is available for your dates, I'd take that one as my first choice.
Dick Taylor