My original (SE) dampers on my Coupe, were knackered at 62,000 (9 years old)- in fact the front o/s damper had no damping left in it whats so ever.
I decided to replace all the springs and dampers with m-sport equivalent Suplex springs and Bilstein B4- these are considered a slight improvement over standard dampers.
I didn't want the B12 kit as for one, it might be better on track but, on bumpy british roads and a quick blast across Exmoor, the better compliancy with the B4 will mean you're not pitched and thrown about as much as the B12 kit- and ultimately that little bit quicker and not so much hard work!
Also B12 kit too low for me with the garage and steep entrance/exit from car parks, local speed bumps, etc!
I also replaced all top mounts, drop-links, poly bushed the f&r anti-roll bars, and crucially a proper all-round alignment by someone who knows what they're doing!
All this made the car feel night & day difference for the better!