I quite enjoyed Najica Blitz tactics overall, so heres a quick summary about what I thought.
Najica is good fun for a quick blast. As long as you don't find excessive (possibly the most I have ever seen in anime) amounts of panty shots offensive or can laugh at the sheer ridiculousness of the ones in Najica (I personally found the amount they crammed in at every oppourtunity amusing, if utterly needless to the anime) then theres actually quite a good spy thriller to be found.
Its a pretty episodic series, with a overall storyline loosely keeping the episodes related. The majority of the episodes are pretty good too, and at only three discs (or theres the R1 slimpak collection) its not that expensive to see it all and is just fun and entertaining to watch without being outstanding.