Factory brushes are expensive and last less than 15,000 miles. But they are easy to replace, all CBX parts are pricey, and the aftermarket brushes, though much less costly, damage the alternator. The alternator is driven by a quirky and defectively manufactured engine coupling that if ignored can deposit metal debris into the engine oil. But this coupling is easy to fix and even easier and advisable to completely eliminate. At 350 watts the US model's charging system is quite powerful; it even out-powered the GL1100, and though the system does not charge at idle, neither do any of Honda's other electromagnet-based charging systems. The alternator is fashioned beautifully, it's all Honda, and it is well-supported by a maintenance knowledge base that is shared with other early 1980s Honda roadbikes. It is easy to disassemble and repair. Being a modular charging system design, the many wire cables and connectors have to be kept up or the system performance will degrade, but this upkeep is not difficult. Given the age and average mileage of these machines, the alternator's two bearings are beginning to need replacing. But it's an easy job and the bearings are readily available types. The electromagnetic rotor will eventually fail, but so do the rotors of similar models and it's easy to replace. The regulator/rectifier sometimes fails at the same time, and is expensive and discontinued, limiting options to less reliable aftermarket substitutes. However, reg/rect units from other Honda models are adapatable and aftermarket ones are at least readily available. The alternator-to-engine square-section sealing o-ring is a unique design, but it is still available from Honda.

Further reading:
The CBX/Denso conversion
Forum electrical deception