But I think the shares are worth around 5BTC and while I wouldn't buy them at 10BTC (I cannot afford to at that price) I'm sure some people can. It's a good place to put your Bitcoins and it's better than leaving it in cold storage or hot wallet. You might have to deal with the fluctuations but if it gets to 5BTC it's not going back down to 4.5 so the problem of fluctuations mostly affects people who get in too late. If you're getting in at 5+ then I would think it's far more risky than getting in right now at 4.5.
Emphasis mine, and I agree with the points in bold. To extend it another step, getting in at 4.5 is riskier than if you'd done so at 4.
If you bought in at a lower price (let's say <2 for the sake of the discussion), the question is not whether you lost or gained money, but how much profit you've made.
I disagree with your statement that share price won't drop to 4.5 once it passes 5; all I can see are those "hold, spartans!" memes on /r/Bitcoin when
BTC/USD was $200+. If x can go up, x can go down, which leads me to your statement that AM is a better parking spot than cold storage; that's only true if AM shares don't decrease in value.