Here's a good example of one of the big concerns I have with Allen:
The play results in a TD, so a lot of people touted it as an impressive play. However, Allen completely blew the pre-snap read. My two biggest concerns with Allen were his poor accuracy and his major struggles with pre-snap reads. Watch the play closely. Allen starts the play looking to his left. He has a 3x1 formation after he correctly motions the HB into the back-field to help with pass protection (reading the blitz). However, watch the CB covering the single WR after he motions in the HB. The CB slides over and takes outside leverage. Look at the single-high safety in the middle of the field. He's shaded to the left side of the OL. That should tell the QB that FS is going to be helping the CB. The CB is taking outside leverage to funnel the WR inside to help.
Look at the other side of the field, he has 3 defenders against his 3 receiving targets. They're playing either straight up or inside leverage. That should tell him that there is no help. What should he do here? He has two options. He can go to the slot WR running the flat route. That's a more risky throw because his timing and placement needs to be perfect or else it results in a pick-six. His other option is to look left right after the snap to bait the FS and then quickly reset and hit the TE on the drag route with a pass in front of him. It's a tight window, but if he places it right, the TE can use his body to box out the defender. Instead, Allen locks onto the only double-covered WR.
I know some will say that he's a young QB and that will come with time. However, the problem is that this isn't a complicated look. It's actually a pretty simple look that even a good college QB should be able to recognize. Imagine what's going to happen when teams start disguising what they're doing. Allen is extremely physically talented, but I don't think he has the mental acuity to be great. I'm not saying he's a stupid kid; I'm saying that he doesn't process things well on the field.