Choosing the right cartridge....

Ortofon Cadenza Bronze is a great match to the VTPH-2A. Not nearly as analytical as the other top-range MC Ortofons to my ears - Ortofon calls the Bronze "warm", I call it "neutral". Excellent price/performance on that combo. Shelter carts can be good too.

I have the VTPH 2A, love it with my Koetsu. The Herron has plenty of gain for its .4mV output. There are probably plenty of phono stages people will notice seem to work well or not so well with certain cartridges. I rather doubt that is the case with the Herron. 2 or 2A I bet its fantastic no matter what the source. Now when it comes to cartridge/arm that might be a different story. But cartridge/Herron I would not worry about.

While there is no doubt I would be in "nirvana" with the Koetsu, the best cartridge for any individual will depend on his musical preferences; analytical for rock, and a Koetsu for jazz and female vocalists are the first generalities that need to be made before one goes into arm compatibility.

Actually I’m a huge Koetsu fan; they’re absolutely my favorite cartridges. For me it just worked out that I keep Koetsus on the main rig with my VAC phono stage plus SUT, and the Ortofon/Shelter on the 2nd system with VTPH-2A. Yes, the Herron will do well with Koestu too - its MC stage is really good, but I still prefer MM mode plus a great SUT for Koetsu. Most Koetsus tend to price themselves well above the Herron, though - and at that point you’re "all in", and then I definitely prefer VAC as the partner. But a Black or Rosewood might make a perfect match with VTPH-2A for a reasonable budget (I just haven’t heard those models). Now that this suggestion was posted by a user, I have to join in endorsing it. 

Koetsus are not genre specific. I listen to a lot of hard rock and heavy metal (when it’s well recorded enough) with mine. Never heard anything do this material as well as a Koetsu. Analytical cartridge for metal? Yuck! :)

The Cadenza Bronze is the one Ortofon model that "gels" with me as a Koetsu lover. Their higher end cartridges strike me as too much like high-end digital. I also like the Shelters for this reason.