I've seen enough of Gnabry to know. Couple of times in the flesh as well. He's superb.
Never really took to Afobe when he was younger, but he hooked me at the Emirates Cup last summer. He was outstanding against Thierry's Red Bulls. Having already caught my attention with his loan at Huddersfield. Right now he looks like player that has been out for most of the last year, so I won't read too much into his his disappointing pre-season.
Aneke I've always loved, but worried (and still worry to an extent) that he's going to have to make it as the team's playmaker to succeed here. Which just ain't gonna happen, despite his quality. Become more hopeful in the last year or so that he can adapt to a proper central midfield role, but still share Nela's concerns about whether he has the right frame and stamina for the role. Seems more of a power player, but I'm sure if Wenger decides that's the way forward, they'll figure it out.