Shock absorbers Bilstein or KONI

Personally I think Koni's are a better choice for street/everyday driving ( softer and less jarring over road imperfections).

I put on some Bilsteins in the back and removed the rear sway bar and it still drives quite nice.

For now sits on Bilstein PSS10's and gets driven on my days off.

I have Koni red's in my MK4 at stock ride height, I think the ride is nice just a bit firmer then stock sport suspension.

I'm running DG springs with Koni Yellows and love the setup.

Koni shocks are the best you can get without spending 3.5k on a set of racing coil-overs. I have them, yes they are that good

I'm running Koni STR.T's with FRPP K springs on my mustang and have been happy with them overall - still do wish I spent a little more on the adjustable's but for the price I can't really say anything bad.

I don't know if it will be the same for the Mustang, but on my GTI I have Koni STrt shocks and they certainly are not OEM+, they are about as stiff as the Koni yellows on the 3rd click up from the softest, they make for a rough ride combined with stiffer springs like the H&R race springs I run. As far as how they have held up they have been on there for about and year including one Upstate New York winter and they still perform the same, They have begun to make a squeaking noise over harsh bumps and I've noticed a little seepage at the top but the housings have next to no rust, no complaints.

I bought my 2003 with some autostore garbage in the front (Monroe or Gabriel or some such crap - don't remember now) and the rather tired OE Sachs/Boge in the back. The damned thing was scary do drive above 35. Installed Bilstein HD 24-019118 ($203.90 for the pair from eshocks) in the front and the 24-214230 ($185.50 for the pair from eshocks) in the back. Very happy with the result. Took the bus above 100 in Texas and Arizona on the way to California this past January - and what a difference this made! It sat on the road like a flatiron on the ironing board. Also, do keep in mind that Bilstein shocks carry lifetime warranty and the company stands behind it 100%. My S6 currently rides on its 3rd set of Bilstein Sport (after 2 free warranty replacements) in the 16 years under my ownership - Bilstein replaced them each time w/o a flinch. Konis are good, but they sometimes leak. Bilsteins wear out but they don't leak. At least in my experience.

Personally I think Koni Reds (better design and build quality, but the same soft ride, with performance gain), are too soft. I've had them on some of my other cars before, and I don't care for them. I've been much happier with the Bilsteins I've installed when compared to the Konis.