Late input, but my $.02:
I have been installing multiple radios in a fleet of vehicles for a number of years, and a CB radio is one of the necessities. Because of the difficulty of finding a place to put a CB radio where the driver can see it and access the knobs in many new vehicles, I started using the Cobra 75WX-ST about 6 years ago. The average time-in-service of the vehicles the radios go into is 4.5 years.
I have found the average time to radio failure is less than 3 years. Many of the failures are 'soft' failures, such as the radio going silent after a couple hours, or sensitivity drops way off. About 3 years ago Cobra started making the mic hanger button out of a fiber or plastic material instead of metal and now the mic button breaks fairly soon after the radio goes into service. Usually less than a year. The radio must have an external speaker, the audio is horrible out of the tiny speaker in the hand unit (no big surprise there) but the audio still is pretty nasty with the external. But the biggest issue is... the customers hate them. The display is hard to see, the backlighting is uneven and the plastic window clouds up in a few months' use. The customers don't like the way the volume and squelch controls are placed. Nobody said anything until about a year ago, and now the negative feedback is fairly dense. I don't care much for the radio myself. At the time I started getting them they were about the only choice for a hand-controller CB radio.
I got several of the Uniden CMX560's before they were taken off market, and bought a dozen CMX760's after that. I personally like the CMX560 ergonomics a little better than the 760. There is no internal speaker so you must buy an external speaker. The available volume with a reasonable-quality and size speaker is plenty. I have no time-to-failure track record yet, but the customer feedback so far says the CMX560/760 is much better liked, except for one person who can't seem to figure out how to adjust the squelch. I don't like paying more than $150 for a non-SSB CB radio but I would like to have happy customers, and that's worth the $50 difference between the Cobra and the Uniden. The biggest problem I have so far is getting the customers to leave the 'Roger Beep' feature OFF.