Just got the V5 duals in with my HE-560 and wow, things just keep getting better and better. More body while retaining detail. However, downsides are it slightly loses too much mid-upper~upper treble, just slightly. Also, the duals seem to add some artifcial sparkle, it sounds something I've experienced with the AD823. It is very interesting, but at the same time it can be very annoying. It is not the problem with the op-amps, but it is actually a problem with modern recordings. Since my majority of music library are modern recordings, it can be fatiguing. It is not sibilance that pierce your ears, but it is more of added sparkle. Going back to NE5532 is noticeable with lack of body, but still sounds good
Definitely like the improvement, the piano solo part in Eric Clapton - Old Love (Unplugged 1992) sounds like heaven. It can sound quite muddy compared to the stock though. Not my cup of tea, but pros outweigh the cons.