Hi everyone! I am interested in running Pokemon Blue, and I would use the Game Boy Player to record my gameplay. Since a while ago, I use the GBI software instead of the original GBP software. I barely see any runs using the GBI software, despite the advantages it gives with respect to accuracy. Is there a specific reason for that? If GBP software is more suitable for speedrunning, I will just use that instead :)

Either GBI or GBP are fine. I think you'll find most people use GBP because it's just more mainstream, and in most cases, people who have the attachment will have the disk too. There's no stigma or technical reason to choose one over the other though (aside from the hard reset fadeout, which if I remember right gives GBI a slight disadvantage)