The failure rate of Mackies verses Behringer is the same, they both use the same switches, Panasonic faders, Alps pots, and basically the same kind of printed circuit boards and pre-amplifiers. And they both are a pain in the but to service.
Most of the time, you have to take all the knobs off and remove a thousand screws just to get at the switches, faders and pots underneath to lube them with CAIG-DE-OX-IT spray or beter. For doing the faders, ribbon connectors, pots and switches for removing the oxide build up which causes static noise or drop outs in the sound. This has to be done every ten years or sooner depending on the environment it is used in.
Behringer and Mackie mixers all get static in their switches, pots and faders after they are exposed to the moisture and air for a long time, again about 7 to 10 years depending on your climate. I worked on both brands. The sealed Alps pots seem to last longer as far as static problems, they just usually need to be excersized from time to time to get the sealed lube inside moved around and the static usually goes away. Don't use thin oils to lube pots, it requires a special thicker lube oil. They are much harder to lube because they are pretty much sealed.
As far as the XLR pre-amps being better in the Mackie, I am not sure on that one. Both seem to sound the same to me. And as far as dependability, both have issues and strengths. When tested, the over sound quality is the same.
As far as paying a much high price for advertising hype and all it's expenses, Mackie wins by a long shot. Behringer has a much lower overhead and much lower advertising costs, so it wins in the price wars verses the same features by a long shot over Mackie.
Not to say Mackie makes bad gear, they clearly don't. They have made allot of innovations over the years that Behringer has definately copied. Behringer likes to copy other manufactures so they don't have to spend the money in research and design. Amazing that they get away with it....still today. Mackie wins for both original concepts and designs by a long shot over Behringer.
But some things Behringer makes is unique and innovative, and actually are not copying other company's designs, rarely though this is the case. Shame on Behringer for making music gear truely affordable to all..........
Both Behringer and Mackie are the same in longevity, if you can do maintenance to them from time to time to keep them both problem and static free.
But for me and many others, Behringer wins over for the price verses value wars everytime. And the older Behringer gear is better made than the new stuff, same goes for Mackie's older gear.
The Behringer MX9000 is good sounding, has allot of Ins/Outs and is a very useful mixer, besides only the power supply failing every 7 to 10 years or so, depending on the heat in your studio. Otherwise very reliable and a awesome price used. Make sure to check all channels and inputs before buying.
The Behringer small format MX series mixers are very reliable and sound very good, especially for the little money spent on them in the used market today. For Mackie's older used mixers people want a premium for them. To me they were way over priced when new, and still way over priced on the used market today.
Behringer wins over Mackie for good value both new and used. My 2 cents worth.........