I have driven so many cars with and without strut bars, and honestly, have not found much of a perceptible difference on the braced cars on the road.
Agree with the sway bar comment. There was a time when you could source a sway bar that was like 30mm (sounds right, it was HUGE) for the Bav and apparently that was the ticket for high performance applications. I am running Bilstein Sports with larger, modern tires, and honestly think I would need to add another 100HP before I needed serious bracing or suspension upgrades for handling to become the bottleneck.