Which is better between getting a visa on arrival at the airport or applying for an e-VOA in advance?

Both are possible, but it depends on your situation. The advantage of applying for e-VOA in advance is that you can reduce immigration clearance time at the airport to about 10 minutes. Especially if you're arriving during busy hours, it'll be really helpful, and since you only need to show a QR code, it's much more convenient. The cost is almost the same level, so there's no financial burden. Airport on-site issuance has the advantage of simplicity—you only need your passport and cash without any additional documents. Even if you arrive late after 10 p.m., the counter operates, so you don't have to worry about time constraints. However, it's known that system errors can occasionally occur when applying for e-VOA, so it's good to keep airport on-site issuance as a backup plan just in case. If you're departing in 2 weeks, you have plenty of time to apply for e-VOA, and you only need to apply at least 3-4 days in advance. For stay extensions, both e-VOA and airport on-site issuance proceed the same way based on the visa you initially received, so either way you can extend your stay up to a maximum of 60 days with one extension. To sum it up, if you want to save time on entry, go with e-VOA; if you want to go without hassle, airport on-site issuance seems like the right choice.