Watching a lot of video of both Beck and Brissett. I am no scout, so take that into consideration. I didn't see very many reads or throws that Brissett made that Beck could not have made. In fact, they look like similar players. Beck seems to be a very accurate passer and does a good job going down through his receivers. He is really good on his timing routes. He puts the ball where receivers can catch it, but does not always make it easy for receivers because he will throw into tight windows. Beck is a big guy and never looks like he is worried about getting hit. He moves slightly to avoid the rush, but nothing like Kyler's scared bunny routine.
Watching Beck last year and Brissett last year, I was really struck by how much time Beck generally got in the backfield with Miami. He had a good line with good protection. Brissett was dealing with a collapsing pocket on nearly every play. Beck will have to get used to having half a second or more less time.
Overall, to me, they seem like similar players with similar skill levels. But we will see.