The thing about highlight reels is that they'll never capture what was wrong with Dobson - he could make a fantastic play that showcased his size and speed, but then the other 9 targets he'd play slower and smaller than he was and probably drop a ball or two outright.
You could put together a pretty incredible highlight reel of brilliant plays by JAG receivers. Just by playing in the NFL, it's a given that they have a lot of talent. But the difference between a Dobson and a good receiver is what they do on the 95% of plays that don't make the highlight reel. So far, Mitchell's acquitted himself pretty well on those plays. Dobson never really did; even in 2013, he showed a lot of promise, but mostly in that you assumed he'd grow into better consistency.