This has a similar scroll wheel to the Hanlin V5, but it is on the left side. A right side scroll wheel, like the V5, would give one more right hand page turn option. The location was probably designed for the Hanvon firmware, since with OpenInkPot any of the number keys on the left can be used for page turns.
As a design, I would ordinarily say it has too many buttons. However, that is perfect for OpenInkPot which can bind an action to each of these keys.