He's got what I like to call phone booth quickness. He can make defenders miss in short areas, and if he recognizes the rush and triggers to run quickly he can get a quick 7-10 yards, but yes you're right, he's not a top end speed guy.
Not comparing the 2 but Mahomes is similar.....runs like a 4.8 40.....I'm not a fan of the using the 40 as an uber important measuring stick for most positions but for QB's its literally meaningless.....quickness is way more important than top end speed....