You know guys, coincidentally, I've been really enjoying PES 2019 ATM as well!

The game looks gorgeous (I think the best looking PES out there, the pitches and the clothing are absolutely fantastic), the ball physics are really nice, and the game overall in terms of playability I've found it very refreshing. The only thing I had with Vanilla AI was that it always seemed to me like "CPU Momentum" was really overpowered, but I've also found that the extensive gameplay modding community has some really good mods that address this.
Also, one thing I wanted to ask is: the "Classic" vs "Challenge" mode in Master League. Have you guys tried the "Challenge" mode, and if so, have you found it realistic? Cheers!