I love my situation too, but I have been on the other end.
I leased two horses for about 5-6 months, and one day the owner emailed me and said that she was putting one of them up for sale (this happened to be the one I got along with wayyyy better). I cried all night long, thought about buying her, etc etc. It turned out for the best, because instead of buying her, I looked for another loan. I hadn't really bonded to either of the horses, so it was easy for me, plus I wanted to be at a bigger barn.
Now I half lease Eddie, and I really couldn't be happier. His owner and I get along soooo well, and she tells me that she wants me to treat him like he is my own. We call and email about him quite often, and that makes me happy because I can tell she loves him and cares about him sooo much, but she still trusts me with her baby. I would have a hard time loaning from someone I didn't feel comfortable talking to.
At this point in my life, I wouldn't want to buy. I like the flexibility of my half lease; being able to go on vacation and not worry, not needing to be at the barn every day or twice a day. I have a lot of other things going on in my life, so this is ideal for me right now...give me a couple years though, and I'll be ready to hunker down with my own baby!