Ian, since you did submit your video, I'll offer some comments here anyhow. I will for magicman2 as well if his video gets put up.
Righto, let's get started - your first words were "Ok, umm..." ! I know it's really hard to get rid of a habit like this. I do it all the time, and I've been trying to cut down. But you do need to start strong in particular. Just go into it. When you're thinking of what to say next, slow down. Don't say it until you have it in mind. Don't be afraid of pauses. These are just things I've noticed in my own attempt to curb this habit. It doesn't sound as weird as I would think if I pause and speak slower but more definitively. And you never hear the pros say umm.
You also don't sound too interested when you say "An interesting fact!" Obviously, the whole thing is baloney - but I think it would be more entertaining and convincing to either say it with full conviction, or to make it obviously tongue in cheek - but go with one or the other! The next thing I would say is cut down on the cutting, or cut at a different point - "If I push this button, your card comes to the top" - "Actually, no, that's just you cutting the deck" - is the logical thought response there, if you know what I mean? Also, careful not to flash the break, it was visible from the front edge.
Another presentational thing that comes to mind is to not narrate what you do. It's another habit that's easy to pick up and difficult to let go of - but you definitely do need to cut down. "Let me find a few cards" is fine - "The ace... the two... the three... the four... where is it ah there we go, the five" - is a bit too much and it sounds like you're just trying to avoid silence. It's ok, just do it promptly, and you'll be alright - but narration does get old pretty quick. On a slightly related note, I'm not sure if finding their card using these five cards is a good excuse to pull them out - I prefer CK's original patter of doing another trick. The reasoning for this comes because of the powerful element of surprise here - see later on.
Yet another presentational thing is to make your actions consistent when the magic occurs. Firstly, I'd limit the shaking, that looked like a really big shake! But to illustrate my point - the first time, you shook the cards. The second time, you clicked. The third time, you did nothing at all. Make it consistent.
Another note I thought of regarding the sequence with the fours - if you do something which requires a "no" answer to the spectators - try and avoid the no. In this case, you could say, for example, "You'd think that it was here... But actually..." It's just a small thing that generally contributes to the whole atmosphere. It's just nice to avoid saying a direct "no" to someone - our words are so powerful. I literally felt taken aback when you said "No, it's here" - and I'm only watching a video over the internet!
The moments after the sequence with the four was a little bit too much downtime. I don't know what happened but it definitely looked like something went wrong. Also, now you're shaking the card, in continuation of my point before about shaking, clicking, and so forth.
So obviously, you did mess up the ending a little bit, but to be honest, I'm not at all worried about that - no biggie, nothing you can't fix with a few more trial runs. But - I don't know if it was a genuine slip of the tongue, or a planned line, but definitely don't mentioned their card in my opinion! The strength of the final moment in my opinion comes partly from surprise. At this point, they have completely forgotten about the selection - I know I did! So whatever you do, don't bring it up...
So, I kinda feel like I've dissected your performance here a little bit, so I feel kinda bad - sorry about that! It's rather long, but don't judge the level of performance by the length of this reply. Of course, all of the above is just my opinion, and I'm definitely not right all the time, so think about it for yourself. That said, as I mentioned above, obviously the ending messed up a bit but I'm not at all fussed about your handling, there's nothing inhuman there. The area to focus on would be your presentational skills, and some small notes/modifications, verbal and otherwise.
