I know it's been a month since you posted, so am probably too late with this reply, but thought I'd add my thoughts in case there's anyone else out there considering a biOrb:
I bought a Baby biOrb a few weeks ago for my male betta, & overall have been pleased: it looks very nice, my betta seems to think it a huge improvement over the 2 gal tank he'd been living in. A few things to consider, however:
1. They say not to use regular aquarium gravel, only their propriety ceramic media -- I don't know why, wouldn't mind hearing some feedback on this! It does come with the aquarium, & can't imagine you'd have to replace it very often, if at all.
2. The opening at the top is quite small -- one arm in at a time (on the Baby size, at any rate)! If you're planning on artificial plants, get the kind that are self-weighted; IOW, you don't want to have to fill the bases of fake plants with the ceramic media provided to weigh them down, for 2 reasons: first, the ceramic pieces are too large to be very effective (don't really fit in the plant base); and second, it's VERY difficult to do one-handed when the media provided doesn't really work! I spent several minutes getting one plant situated, just to have it knocked out of place when I tried to place the second one.

One reason this is so trying is that you can only place the media (read, gravel) around the outside edge of the biOrb, so as not to block the filter.
3. I find it rather difficult to siphon/vacuum. I wound up buying one of those siphons with a bulb pump on it to get it going (hasn't arrived yet, so hopefully that will solve that problem!).
4. I live in the Houston area & it's been quite warm (unbearably hot, actually) since I moved my betta to the biOrb, so water temp has been stable around 79°-80°; but come winter I will need to add a heater. I anticipate having to buy the proprietary mount and most likely the heater (we'll see) made especially for the biOrb.
5. You'll probably have to buy their proprietary filter replacements. I know some people actually put together their own simple filters, but I don't feel I'm that savvy yet; nor have I really taken a good look at the thing to see how it's constructed. If you're insecure like me, you'll wind up spending $$ on replacement supplies made especially for the biOrb.
6. I have clamped the aeration tube for a very gentle aeration; otherwise it's a bit too vigorous for my betta's taste! (yes, they do provide aeration).
Taking all of that into consideration, I am still enjoying my biOrb. It looks lovely (which is the reason I bought it, as my old tank — besides being too small — was an ugly thing I didn't like having on display); my betta seems to like it (especially since he's now got more plants to hide in & rest on).
Hope this helps!