i would say go for the experience, i am an appleby fan, love the fair, there is an atmosphere like no other, sitting at the river and watching the horses swimming and being bathed, watching them all on millionaires lane, so many different horses, cobs, trotters, its incredible, all the differnet stalls, it is a really good day out, if you get there about 8am in a morning you can generally park in the village then watch everything come to life, seeing all the old bow tops is incredible all the detail there is an element of romance about them.
The other side of it is, remember that it is a gypsy fair, you are seeing an insight into there way of life, you may not agree wih alot of what you see, or not like things that you see, but you have to try to be impartial, there are good and bad in every walk of life, if you meet any of the old horse men , nicer more genuine folk you will never meet, the knowledge they have is second to none.
It will be a day that will leave you with many questions, and a mixture of thoughts and feelings, but it is worth going just the once, just be open minded. love it or hate it appleby horse fair, has a long long history, it would be ashame if we lost it.
The fair is not what it used to be, not as many horses, the introduction of the passport system seem to have a knock on effect there, and as folk have said, camping on the road is not ment to happen anymore, there are new restrictions put in place evey year, which are slowly taking the heart out of appleby horse fair.
At the end of my ramble, my advice would be go but take your wellies.