Strut braces are good if you intend to run lower profile tyres/bigger wheels or want to take your car onto track as it prevents the front from flexing, very noticbale in front drive cars with more than standard power. My integrale EVO has a front one as standard, as has the new Nissan 350Z front and rear amongst other higher performance cars out there with them.
Tightens up the front of a cinq nicely, makes turn-in feel a little sharper.
You should only really notice a difference under fast driving, especially twisty roads. If you don't thrash it about you probably won't feel the benefit.