At this point I've owned four trikes (I still have two of them) and I've
test ridden at least 6 others. The design of the tadpole steering (two
wheels in front, one in back) is fairly simple yet there is quite a bit of
variety in implementation. If you are considering a purchase, test rides are
certainly required. Examples:

The Deltas (two wheels in back) tend to steer like ordinary bikes although
you still have the Under Seat or Above Seat choice.

Tadpoles have a bit more variety. When I test rode the Catrike I crossed it
off my list immediately because I didn't like the feel of the steering. I
understand that they have re-designed their steering for 2005 so I might
feel differently now.

Greenspeed and WizWheelz have more conventional tadpole steering.

There are a few trikes that have a stick for steering. WindCheetah is the
most famous. The stick is very responsive. On my first ride in a parking lot
at low speeds I had the WindCheetah up on two wheels. That never happened in
real riding.

Tricruiser has "one sided" steering as standard with more conventional "twin
stick" steering as an option. I've never ridden one with single stick
steering. I am taking a friend of mine to look at a single stick model,
however. He has a hand injury from a car accident that is not going to
improve. The only option he has for cycling is to find something that he can
completely control from one side. The Tricruiser with a single stick, disc
brakes (front left and right controlled by a single brake lever), and a
Rohloff Speedhub should be able to put steering, braking, and transmission
all on one side of the trike. We'll see if it works for him.

The sidewinder has front wheel drive and rear wheel steering. The feel is
quite strange compared to everything else. I'd be afraid to ride this trike
anywhere where you encounter high speed although the video on the website of
the rider doing tight 360's is fun to watch. I wouldn't do it myself,
however.

So your simple question doesn't have quite the simple answer that you might
expect. If your serious about getting a trike you've got to test ride them.

Jeff