1600, 1700, 1800 and 1900 loops are all Full Hookup sites. All 4 loops are in one large area of the campground. Full Hookup sites are just fine with us. Now that all loops have Cable available, it really doesn't make a difference. All sites have some level of sand with Full Hookup sites having the most. So if sand is a concern, those loops might not be for you.
Site size throughout the Fort varies. In the 1400 loop (one of our favorites), which is a Premium loop, there are sites that are smaller than those in the 1600 - 1900 loop and there are a few sites in the 1400 loop that are tight getting into.
Spring Break is our least favorite time to be at the Fort. Too darn crowded and the parks are way too crowded for us. There is no Disney Magic that time of year, especially towards the end of the Spring Break season.
-Michael