we had one and loved it but bruiser did not. he prefers smaller quarters :) the filter is adjustable but you may still need to baffle it depending on your fish. also, it's longer then it is wide so finding the right spot for it could be a challenge. i'd repurchase it if i didn't have such a picky, spoiled boy.
They one I currently have is round. When My betta is close to the walls he actually disappears from view because of the distortion. Since that is were he likes to hang out I rarely get to actually see him. That's why I think I want the longer viewing area. The spot I have for it is long but slender so I that a 10gl would look awkward in that spot.
I have had one for maybe 6 months and I love it. I have one male betta in it and he seems to enjoy it. I have a small non-adjustable heater in it and with the florescent lights it stays a nice 78 degrees. Plants grow nicely in it as well.
I have been thinking of getting that tank, I think because of how long it is, as long as the filter is capable of handling it, could have some other fish besides a betta. I could be wrong, but just because something is a certain amount of gallons doesn't always mean how many fish you can get.
Hmmmm, I think that more than one betta would seem like too much. The tank isn't very deep. It's more long. It's also hard plastic (versus glass). I haven't had any issues with the filter. The flow is adjustable.