I've experienced it anywhere from one to ~five times a year since I was 13 years old in varying degrees. Sometimes it's full-blown dreaming until I lose consciousness again and wake up in the morning or half an hour later, sometimes it's a dream which slowly fades until it stops and I'm awake and lucid again. Then there are times I just can't move or where I wake up looking at my alarm clock and feet and it feels like they're a million miles away and my arms would have to be as long as the Chinese Wall to touch them. Sometimes little things just don't seem right, like a gardening trowel on top of my keyboard or a raspberry vine growing over my bed.
The first time it happened I was close to panic at first, but it turned into what I still consider the most important experience in my life. All the occurrences since then have been very meaningful to me and often occured when I was feeling mentally tired and served to refresh my mind. Recently though, I've been having a very unstable heart rhythm and I had an episode of sleep paralysis while this was going on. It wasn't fun, but I realised that even if I had physical control it wouldn't have been any better and I think all-in-all I was less worried and stressed than I would've been if I were awake for it. Then again I might just have dreamt it because it's happened before when I was awake, like a memory manifesting in a dream or something.