We stayed in Chanctonbury and Silver Birch cottages. Both were superb - pretty similar, except that Silver Birch is a little smaller and Chanctonbury (2 beds) has a dishwasher.
Owner Emma has supplied almost everything you could want for your stay, including freshly-laid eggs! It is thoughtfully set up, very clean and extremely comfortable. Showers were a highlight for me - spacious, with a fixed head and a handheld one, great water pressure and always hot.
Gallops Farm has wonderful views across the Downs. Lovely Findon Village is just over a mile away, along a fairly steep farm track. Each cottage is a proper little home - I'd have been happy to stay for weeks.