Merino wool jerseys are worth the premium if you're doing multi-day rides like touring or bikepacking. The big advantage is odor resistance—merino naturally fights bacteria, so you can wear it for days without smelling. It also regulates temperature beautifully, keeping you comfortable across a wider range of conditions.
The tradeoffs are real though. Merino dries slower than polyester, so if you sweat heavily or get caught in rain, you'll stay damp longer. It's also less durable, meaning it can develop holes more easily, especially under a loaded backpack. And you'll typically pay a significant premium over synthetic options.
For single-day road rides or hot-weather commuting, polyester blends usually make more sense. But if you're living on your bike for days at a time or hate that lingering gym-bag smell in your gear, merino is a game-changer.