I said "arguably" because I personally consider the RG 2009 SF the most important match between the two. I think even Federer wouldn't trade that SF victory over that US Open final he lost.
You might have a point. That was the semifinal, but it was basically the de facto final. I knew whoever won the match was taking the title and it was for Federer's Career Slam. Still, it's hard to consider it more important than an actual final.
h2h is exaggerated, i agree. after all, since that easy victory in the AO 2009, most of their matches have been fairly close with federer prevailing in all the tight ones (except of course that USO final).
i don't think federer is such a bad match up for del potro though. in the last few years federer has shown to be vulnerable to big hitters and big servers. his tight matches in the recent years to the likes of raonic, berdych, isner and del potro seem to be a testament of this.
It's a bit exaggerated. They kept facing in like every tournament during Del Potro's comeback, and also three times during Juan's teenage years.
Federer is a terrible matchup for JMDP though. He's vulnerable to aggressive big hitters. JMDP's high % big hitting (with a lot of margins) doesn't cause him as much trouble. To beat Federer, Del Potro needs to leave his comfort zone and really go for the lines. When he employs his usual big hitting down the middle with big margins strategy, Federer ends up messing up his rhythm with slices, drop shots, spins.... Federer's variety make him a terrible matchup for Del Potro.