For me, the JH13 (pre-freqphase) excels just about every genre of music save for Classical and vocal centric genres.
While other custom makers may excel in very specific genres, the price to performance ratio for excelling in specific genres, make them too costly. Almost as if the makers want buyers to have a "collect them all" buying habit. Great if the person has lots of cash to burn, not so for audiophiles on a budget, or those who just want to have one great custom for listening any time, day or genre.
JH13 and the other JH family of customs are what i'd call the best in their category, giving the best performance across without finding them lacking in any parts (by all except the most discerning of customers).
Sonically, built quality and price point wise, the JH series is arguably the most balanced.
I think it speaks for itself when JH has kept their custom series without refresh in the past 6 years, despite many new players coming and going.