Not referring to the HF products or marine products. I've worked on the 746 a few times and they're complex but not hard to work on. They do have a common issue with the serial port failing due to a safety fuse blowing at ridiculously low amperage levels. Easy to fix, go with a slightly bigger fuse. (Surface mount.)
My issues with Icom relate to the dealer/factory interface with regard to technical support for problems found in certain portable and mobile VHF two way radios in the Icom lineup, where the factory denies the issue even exists, meanwhile my customers are experiencing 5 percent transmission failures in digital modes, under excellent signal strength conditions with no multipath issues at play, and a continuing failure to acknowledge the internal trace failures occurring on the main PC boards of multiple mobile radio types. Meanwhile I'm jumpering across traces to power up the regulators on radios on a wholesale basis.
My opinion of the quality of the PC boards that Icom has used in some radios is not very high. While the radio design may be good, if the PC board traces fail internally, that can be devilishly hard to track down and fix.
I also encountered absurdly high PA device failure rates on certain F6061 portable radios, along with some other models that use the same output device. I got really good at replacing those PA devices individually, though Icom suggests replacing the PA board. Well, I guess they don't expect techs like me to have da mad soldering skillz. But I do.
Surface mount is no problem. You just need some different tools and some training.