The VSL Rieger might look a bit daunting, but I think that is a big reason why this organ if fact turns out to be so usable.
The interface has a lot more controls on it for using it like an actual organ. I find it so much easier to use than other Kontakt organs I have as a result.
Trust me, the organ has adopted useful concepts that are still not in use in modern software (but should be!), so any software organ that tries to replicate even half of these feature is going to end up easier to use as an organ. And the VSL achieves this quite well, it is the first software organ where I feel at home with the features like on a real organ. They even added an "all stops off" control after user feedback... a must for any real organ, and is missed in almost all Kontakt organs.