Quite mechanical
This piece is known as "Adagio in G minor" and is commonly attributed to Albinoni, a baroque composer, but actually written by someone called Giazotto or somesuch, based on a few measures of Albinoni's.
Here's a recording on youtoob:
http://www.youtube.com/watch?v=XMbvcp 480Y4
I'll have to admit I didn't fancy the cover that much, it could really use some smoother dynamics. Also, having a 100% rigid tempo and playing doesn't bring out the music well, it feels pretty dead and robotic. Not that baroque (or rather "neo-baroque" in this case) is nearly as extravagant as say romanticism with regards to flowing tempo and such, but still. The cadenza (02:30) is supposed to be lyrical and flowing, not mechanical. Three pianos also feels just a tad overkill, I recall playing a relatively convincing arrangement for one piano.
Kudos on remembering the whole thing though if you didn't have any reference, sounds pretty spot on me, though it's been a year or so since I played it or listened to it in its entirety.