The price makes this a good buy... it's not practical since these aren't ships your character's are going to fly or fight.
It does provide some information on naval battle groups - but if you're looking for that I'd recommend the excellent Traveller's Aide Supplement on Fighting Ships of the Imperium. Not only does it cover the important parts, it explains the theory behind constructing a warship - and provides examples that could be used in game.
LIKED: This is fun for the same reason the original Deities and Demi-gods was fun - stat porn. However, these ships are much more lethal than the old deties. ;)