I'll just add a little value to this review. I own the original SV-1 - not sure how old mine is as I bought it pre-loved. I've had it for about four years and gig it regularly. I have no opinion on the featured Roland as I've never played one. Looks cool though.
Firstly I need to correct an error of fact: The action is not a Kawai RH3, as our leather-jacketed friend suggests at 1:35. It's Korg's own proprietary RH3 action.
I won't necessarily challenge or agree with the reviewer's opinions, they're his own. I'll just add a few thoughts of my own.
Pros:
I really like the action and find it very easy to play. If I compare it to my acoustic baby grand it's a little heavier and less responsive, but it feels very nice and even a player of my moderate capabilities can get through some fairly quick licks on it without much trouble.
It sounds really nice. The EP sounds are excellent. The amp sims are a winner and you can add some really interesting colour to the EP sounds. I like the acoustic piano tones too. Some folks don't get along with Korg piano sounds but I'm more than happy with them for live use.
Control surfaces are super simple and easy to use. This instrument has the easiest to use UI of any keyboard I've ever owned. This is partially due to the simplicity of the instrument itself. Not a bad thing, in my book.
Cons:
Doesn't have a great deal of versatility. It's a stage piano that specialises in EP sounds. You can dig a bit deeper into it with the software editor but it does what it does. Can't store a huge amount of patches on board at any one time, and it only has slots for eight "favourites."
Can be a bit tricky to work out what's going on on a completely black stage due to the fact it has no digital screens.
Very heavy, not the simplest thing to transport. I also had to get a road case custom made due to its unusual shape.
On the subject of shape, the retro styling may or may not be your cup of tea, but you can't rest anything on top of it.
Overall: I really do love my SV-1. I can get "stuck" on it for hours noodling just because it's fun to play.