Well, I've never seen a more "exaggerated change of direction" than Edelman's jump cuts, and he seems pretty successful to me.
It seems to me that what helps make any WR "successful" - or any player at whatever nominal positional designation, for that matter - is how willing his coaches are to optimize what he offers, as opposed to trying to force him into some rigid, narrow, idealized positional template. WRs come in all kinds of different shapes and sizes with all sorts of different physical abilities and skill sets, or, I should say, portions of a very broad set of the skills that "a legitimate WR should have".
To me, Patterson appears to have decent straight line speed - maybe not quite as fast as his timed forty, but still fast. He also seems to have very good explosiveness. He doesn't appear to be anywhere near as naturally agile as a guy like Edelman, nor any kind of "master of footwork", but he does appear to have some fairly well-developed moves/avoidance techniques which, combined with his burst and size, enable him to run through or around many tackle attempts. He's gotten a lot of YAC that way - and return yards - over the course of his career. These combined traits also make him a good blocker and enable him to get sufficient separation on some types of routes.
Patterson seems to have good vision for the incoming pass and very good hands up to a certain depth of throw. What I mean by that is - he seems to be a very reliable pass-catcher on short routes, and on some intermediate depth routes, that put him in a position to be (mostly) facing the QB - crossers, slants, curls, comebacks, etc. However, he doesn't appear to be able to "see the ball" well enough to consistently make the body adjustments to reel in over-the-shoulder/back shoulder throws where he has his back turned while the ball is in the air. But then, he's highly unlikely to be required to run those routes very often (Edelman isn't, either). In the past, he's shown that he can catch some contested balls and some that are not quite on target (he can adjust some).
Patterson doesn't appear to understand all of the reads and route-options off the stem for every type of route (and certainly never will, at this stage in his career), but he does appear to understand those things very well for some routes - certainly enough to be useful now - and there's still at least some chance that he may improve a bit.
I think that Patterson is a good WR - for more than just "gadget plays" - and can be a successful role player if used properly. While his physical abilities and skills don't fit neatly into any of the three WR categories that most fans think of most often - deep threat, intermediate-range possession receiver, slot guy - it doesn't mean that he's NOT a legitimate WR. Not to me at least.
How many opportunities Patterson gets in order to be deemed "successful" by the fans this season depends partly on how things work out for each of the many, many other viable passing targets on the roster - individually, and as a group - and partly on what vulnerabilities in opposing defenses that McD and Brady choose to attack each week. He could end the season with 18 catches on 24 tgts for 160 yards and no TDs. He could end up going 32 for 48 for ~300 yards and a TD or two.
