The Castano debate has been very entertaining. My favorite kickname is "The dog strangler", for Mourvedre. It can be a handful in youth. Personally I think the Costano needs 4-5 years before opening, so doesn't surprise me that it was better day 2.
You can go for a lighter extract and make a light weight and colored wine for early drinking, but if you get any maceration and you are not named Fred or Matt Cline, Mourvedre should not be opened until it's 5th birthday at least.
"Tasting? That means nothing!...How does a wine DRINK....that's the all-important thing" Paul Masson