Recs.
Updated
G910 Orion Spectrum is the 2016 version of this keyboard and is an update from the 2014 Orion Spark and Logitech says the changes where made because of user feedback from the previous model. Some of the changes is a changed wrist rest to a more straight edged design and the Romer-G mechanical switches stayed but they changed the keycaps into a more flat shaped design compared to the sharp edged sort of concave versions. Other main features like the Romer-G mechanical switches, "Intelligent RGB lights", Anti-Ghosting, 9 G-keys, dedicated media keys and Arx Control support is included in both Orion Spectrum and Orion Spark.
Specs
Pros
Pro Individual RGB backlighting
Each key can be individually coloured, allowing a wide range of profiles to be set up. This enables the highlighting of important key groups in games, for instance (some games will have preset profiles for this).
Pro The key switches give a nice response without making too much "clicking" sound
Cons
Con The price is a bit too high
Some might have bought it when there wasn't many other of the options available today from Logitech but it might be worth looking at the cheaper models unless you are looking for some very specific look or characteristics.