Never tried one in the sim, but I've flown plenty of "sticks".

Compared to a trainer, the stick will be more neutral, it won't roll out of a bank on it's own, it won't pull out of a dive on it's own much. On the other hand, it will roll cleaner and "groove" better than the other planes you've flown. It will probibly have a higher top end speed, faster roll rate (unless you really increased the rates on the spacewalker or trainer), and more elevator authority. Landing speed on most sticks is only slightly higher than a trainer, and some of them (with flaps, etc), can actually land slower than your average trainer. Sticks usually have real gentle stall handling as well.

If you read posts on here about flying a 4* vs flying a trainer, you'll get the idea. A 4* and most sticks fly in a simular way. If you use a 4* or such on your sim, you should do fine on a stick.

After flying for a little while, most guys find sticks easier to fly than trainers because they stay where you put them, rather than trying to always get back to level flight.

Of course, you can also put a lot of power, a high pitch prop, and high control rates and an aft CG on a stick, and it can be an entirely different beast, and a heck of a lot of fun.