The Hard Dog Deuce Roll Bar
After an extended deliberation, I decided to get the Hard Dog Deuce roll bar as a safety precaution: it's comforting to know that in the unlikely event of the car flipping over, I've got some decent protection for my head and neck.

What I hadn't realised is how much the roll bar would improve the rigidity of the car. Even on the relatively easy going conditions of the motorway on the drive home, the car was clearly stiffer, and hitting seams in the concrete and cat's eyes with the rear wheels had far less effect on the stability of the car than before. And it wasn't exactly sloppy to start with.
On more challenging roads, body roll is much better controlled, and mid and late corner traction is improved - you can plant the loud pedal harder and earlier before the back end breaks away.
This is all doubly impressive to me because my car is a '97 model, with all the factory bracing (lower front, lower rear chassis and cockpit braces), to which I have added the I.L. Motorsports aftermarket front and rear lower braces and an upper front ("strut") brace. In spite of all the factory and addition bracing, the HD Deuce still produced a very obvious improvement. Further, I've been using the car for the winter with the hardtop on it, which does add a notable stiffness to the rear end (as observed by others), but the Deuce is a step forward again. In fact, with the Deuce, there is barely (if any) difference in the stiffness with and without the hardtop.

Equally praiseworthy is Performance 5's fitting. They were patient and conscientious, and despite the long installation time, never seemed to rush. The mounting holes are all properly and copiously protected from rust, and the cutting and refitting of the trim is as professional as the structural work.

In conclusion, in terms of value, the cost of the roll bar is more than covered by the improvement in the handling of the car. The extra safety of the roll bar can really be regarded as a bonus. And Performance 5's fitting is nothing short of superb.
Performance 5 Ltd