My sister has the 47cm Atlantis, and has handling problems with it.
Here's her description:
The bike is generally over-responsive to input. Any small changes in pressure to the bars result in surprisingly large turning deflection, to the point where it is very difficult to ride with just one hand on the bars (to attempt to drink from a water bottle, for instance). At very low speed, the bike tends to wander, while at higher speed, it holds a line well as long as both hands are on the bars.
She has tried different bar heights and tires, no luck yet sorting out the problem. I'd be interested to see how you like the bike, if you get it.
Hopefully you can test ride it before you buy, and see if you have these problems.