It really depends on your needs. If you're looking for higher CPMs and faster payouts, Adsterra might be a good option, once you reach their payout threshold, typically around $100, the payment hold is only two weeks, compared to Monetag’s standard 30-day hold. However, with Monetag, once you reach a certain earnings level, you can qualify for a 4-day hold and weekly payouts.
That said, I’ve had negative experiences with both platforms. Adsterra randomly disabled my ad serving without any explanation, though they did pay the outstanding balance. After that, I simply closed my account. With Monetag, my account was suspended once, after some back-and-forth communication, it was reinstated, only to be suspended again later. I got frustrated, but eventually, they unsuspended it once more, and things have been stable since.