Never been round the xc at longwood but knowing how run down the rest of the place is i'm guessing that wont be much better.
Horselands is ok for schooling (all ive ever done there as its 5min down the road) in my opinon but then i havent been there for a few years, lacks terrain (flat flat & flat lol) but they did have a good selection of jump when i last went there.
If i had to chose between the two, i would without a doubt go to horselands, hope that helps