This is a clear 10, no doubt about it.
Gentle Giant's music is just the perfect candidate for the "surround treatment". SW took full advantage of the 5.1 capabilities, and this is noticeable in almost every track. The visuals with lyrics are a nice addition but can be distracting. I'm not a fan of this illustration style, but I've enjoyed the watching/listening experience anyway.
IMO, this is a must-buy for surround lovers. It's also worth considering Octopus and TP&TG, should you wish to get the full picture of Gentle Giant in surround (I've found Knots from Octopus and Proclamation from TP&TG to be particularly effective in 5.1. The live piece included in Octopus is also essential).