I have only recently `discovered' IQ. I now have several of their albums on CD and also the 20th anniversary gig on DVD. I did purchase their live `Living Proof' CD but quickly flogged it on eBay - a poor recording if ever I heard one!
`Subterranea: The Concert' is a completely different piece of work, and I would, for the most part, agree with pretty much everything said by the other 4 and 5 star reviewers (see also the studio album reviews).
Yes, it is always a matter of personal taste; whether you give an album like this 4 or 5 stars depends on whether you prefer studio to live, or whether you believe the whole concept is derivative, or even what kind of day you've had. Personally, I am playing this album to death in the car. I don't care that I only get roughly 20 minutes each end of the day to listen to this 2-CD extravaganza, or that I have yet to listen to it properly on a decent hi-fi system. I really like this album and it makes my journey almost enjoyable. In my book that is praise indeed!
So, despite the occasional nit-picking, take a view on those 4 and 5 star ratings by prog fans. If you enjoy the music of Genesis, Marillion, Arena and Pendragon, I reckon you will appreciate this album in your collection. As for the studio version? Well, I followed the advice that said the live album had the edge and have not regretted the purchase - I would like to listen to the studio version out of interest, but am well satisfied with the concert. The overall quality is more than good and the audience are not particularly intrusive. As for the vocals: no complaints at all (listen to `Living Proof' and then you can criticise!)
I also highly recommend `Ever', `The Seventh House' and `Dark Matter' by IQ - great studio albums.