Since I own a tire/general automotive repair facility, I switch things like tires and shocks on my vehicles pretty often, so I can see what the differences are... having said that, I don't have recent personal experiences with Bilstein, but I
do have lots of personal experience with KYBs, Gabriels and Monroes. All of my personal experience is with our trucks - a '95 Exploder, an '83 F250 4x4 and a '76 C20.
From a business point-of-view, I
love KYBs because KYB will adjust defective shocks with no questions asked and no need for an original invoice. This makes me and my customers happier. Monroe claims to have a "lifetime" warranty (like KYB), but they want documentation and generally make it a pain to make an adjustment on shot shocks. Gabriel is worse yet, and is so bad in this regard that it is now difficult to even find them in our town.
From a ride and handling point-of-view, I have found that each brand has its own strengths. For example, on vehicles like Exploders that tend to snap your head back and forth when entering a driveway, KYBs Gas-A-Justs exacerbate this problem, while Monroe Sensatracs minimize it; Monroe Reflexes fall in between the two in this regard, but are closer to the Sensatracs.
On vehicles with soft suspensions that tend to wallow in corners, the Reflexes are superb - maintaining the soft ride, but controlling the wallowing and body roll. They really have to be experienced to be believed. Sensatracs don't control the rolling and wallowing as much, but they are more effective than "stock" shocks. The Gas-A-Justs will definitely stiffen up the ride and improve the handling, but some people don't want to make the trade-off.
On stiffly sprung vehicles, like my F250 (which has leaf springs all the way around
), the Gas-A-Justs tend to allow softer response to bumps than Monroe Gas Magnums, but they damp large ride motions more effectively. For example, near my home is a very curvy road which has lots of potholes and bumps in all the wrong places in the corners, and over this road the Gas Magnums pound severely, yet they allow excessive uncontrolled body motion. In contrast, Gas-A-Justs are much more supple in absorbing the pavement imperfections, but they very effectively damp body motions and make cornering more predictable and less hair-raising at speed.
As far as what I see in shock/strut failures in my business, I have seen EVERY brand fail, including the "exotic" euro-brands. The lowest failure rates (in my experience, again) are KYB and Tokico. Some of the Hondas and Toyotas that come with them on an OEM basis go extraordinary distances with little loss in damping ability or leaking.
Having said that, I tailor the shocks/struts I recommend to the driver and vehicle. It is not always most important to a customer that their shocks/struts last the longest as it is that they provide the ride and handling characteristics they desire.
Whew!
