We haven't seen enough from Angeli to make any concrete conclusions, positive or negative.
But if we're going to make a current assessment of him based on things we've seen, not just based on dislike for the current starter then there are some pretty clear cut things we can say.
1. While he doesn't have a cannon for an arm, he has enough arm to make all the throws, he has touch and accuracy on deep balls and and short to intermediate passes.
2. He's a gamer who seems to find success even on what appear to be sloppy/broken plays and guys seem to want to play for him.
3. While not a dynamic runner, he actually has good mobility and running ability, while not enough to scare defenses it is enough to make them pay if they ignore his legs.
4. His field vision and ability to go through progressions seems good when he has time and protection in the pocket but appears to fall off rapidly when pressured, leading to some first read/bad decision type 'forced' throws.
5. He doesn't navigate the pocket real well when protection breaks down, this along with poor pocket movement decisions (not a lack of mobility) and holding the ball too long leads him into unneeded sack opportunities.
6. He's sometimes a little sloppy with his ball security when trying to make a play.