Bettas vs. the Fluval Edge

On several forums, including this one, when someone mentions putting a betta in a Fluval Edge, concerns are raised over whether or not the betta will be able to find the small opening in order to breath.

I wanted to start a thread to gather some anecdotal evidence from folks who have kept or know someone who's kept a betta in either the 6 or 12 gallon Fluval Edge. My hope is that with more real experiences reported, folks will be able to make an informed decision rather than one based on speculation.

From the very few personal experiences I've read so far, success seems to rely on the individual betta. Most report their betta has no problem finding the hole, but I know of at least one person who says their betta just could not learn where it was, so he took him out.

I have the 12 gallon Edge, and my betta has not had any trouble at all finding the hole. He's very smart and adventurous, though, and there isn't a nook or cranny--top, bottom, or in-between--that he doesn't explore or hang out in.

Someone mentioned possibly training a troubled betta by placing a covering on the glass parts of the top so the only light source is the opening. That sounds like a good idea to me.

Since there seems to be evidence going both ways, my advice to anyone wanting to try a betta in an Edge is to make sure you can monitor him for several hours until he seems to learn where the hole is and be prepared to lower the water level or re-house him if he can't.

So, betta/Edge owners, what has been your experience?