Well, I consider myself a 'skilled' hobbyist, and I use the word 'skilled' to mean that I can do an above average amount of sleights.
But, this move, even with some kind words from Midas Kid, is still something I'm ever improving on after about 2 years of practicing.
It's really quite a gorgeous little thing, and ok, I don't practice all day every day, but it's a move that I think becomes 'easy' quite quickly, but getting it totally right is a real quest.
It took me ages to get it so I was happy, and as I said, I'm quite happy with most card handlings. But being fair, I would say that if you're happy with the feel of cards in your hand, this is about a month of hard work to get it looking smooth enough to be fluent.
And this ISN'T one you can practice in a mirror, which is a bit of a bummer. (well, at least I personally found it difficult to practice in a mirror... maybe we just have weird mirrors in our house

)