Ask HN: What surprised you about Estonia e-Residency and running an Estonian OÜ?

From the official information online, joining the e-Residency program and setting up an Estonian company seems relatively straightforward. I'm considering using an Estonian OÜ for a SaaS business and would love to hear from people who have actually gone through the process. What surprised you after becoming an e-resident and establishing your company? Were there recurring costs, compliance requirements, banking/payment issues, tax complications, or other operational challenges you didn't anticipate? How easy has it been to run the company remotely? Have you ever needed to travel to Estonia to resolve an issue? Looking back, would you do it again? What do you wish you had known before getting started? I'd appreciate any lessons learned, gotchas, or advice from current or former e-residents.