Chassis bracing: What works?

Been looking at K brace, jacking rails, IRS sub-frame support. The jacking rails don't look like they are worth the weight they add. So, I was wondering, what had a positive impact on performance and what didn't?

BMR 4 point brace works nicely, not sure if the Steeda IRS braces are really going to work for road racing...I think they are more for drag racing.

The Steeda jacking rails are more fore ease of jacking the car up, great if you like to tinker a lot. The IRS braces made a difference in my car coming out of a corner there was always a sense of detachment/movement before hooking up, after the braces were installed there was a noticeable sense of hitting the gas and instant traction/hook.

K-member brace and Strut tower brace made a nice change, definitely worth the money in the responsiveness of the steering, eliminated a feeling of delay in response to the steering.

My 2 cents