Most bent arm FH's are built pretty much the same. That's true for McEnroe (continental grip, closed to neutral stances), Lendl (eastern grip, neutral stances with occasional semi-open), Sampras (eastern, semi-open with occasional neutral), Agassi (extreme E/mild SW, semi-open with occasional neutral), Kuerten (SW, semi-open to open), Roddick (W, semi-open to open), and all points in between. There are some dissimilarities w/r/t ultra-modern westerns (Sock), but those differences aren't relevant here.
The main things that change when you change grips, assuming you're hitting an otherwise traditional bent arm FH, are the contact point, the swing path, and the swing radius. Those two things, in turn, combine to determine the follow through. From Mac's out-front-rollover, to Agassi's over-the-shoulder, to the full WW of the more modern guys. These aren't individual flourishes; they're natural consequences of the physics of the swing.
Medvedev's grip seems to range from Agassi-level moderation on some shots...
...to full SW on others. You'd expect that to result in some over the shoulder finishing, and some lower, more windshield wipey stuff. It does.
I will say that for a modern ATP'er, he has a pretty large takeback much of the time. Not full on WTA stuff, but more like Safin used to hit it most of the time, before the abbreviated-takeback revolution had a full head of steam. Back then, the shortened backswing was more a characteristic that would show up when time was limited by fast incoming shots.
Indeed, his FH reminds me more of Safin than of anyone else who comes immediately to mind. And having come of age as a young Muscovite in the era of Safin, this is hardly surprising.
