hi
I use it all the time - Have had my kefir jars going for over 3 years now.
I love it. I use it instead of yoghurt for lots of things, over cereal, in recipies, in breadmaking, also making a kind of fresh cheese by simply straining it (it's curdled already through the fermentation process).
OH thinks it's a bit too tart, so we have a yoghurt maker as well, but I porefer it that way. The tartness actually depends on how long you leave it, I usually leave it a tad too long (3 days). However if you have a lactose intolerance leaving it long enough will reduce the lactose to almost nothing making it a 'safe' dairy option.
I don't have my own milk (yet) so I use shop-bought full fat milk, but I don't see why fresh goats milk would be a problem. The fermentation process is stronger and more 'live' than in yoghurt - I never boil my milk and it works perfectly well. Apparently the fermenting bacteria have a conserving function as well: the milk doesn't really ever go off, I never really rinse the kefir grains, I just strain and add new milk (In regions where kefir is traditionally eaten, flasks are simply refilled with milk when empty.)
If you are after some starter grains I'll happily send you some if you pm me - I bought my grains on Ebay.
After a while you always have too much off it as it multiplies like mad - the dog eats some sometimes, and the chickens love any surplus kefir too