Buying used or grey, no AD nearby

Considering a Chronomaster Sport Boutique Edition (with tricolor bezel) or maybe a Defy Skeleton. There’s no AD nearby. You can just buy online direct but the premium seems hard to justify. I’ve bought several watches used or grey new/unworn including rolex, jlc, omega, seiko, oris so generally aware of pros/cons of this. But, at least on the usa, Zenith is a bit rarer than these brands and doesn’t have an AD within several hours of me. Is it easy enough to get service? Any other issues unique to Zenith to consider here?