Abso-f***ing-lutely!

I agree: original and good idea. One of my favourite series. All the seasons are good, but seasons 1 and 4 stand out.
What I love about it is that it isn't one to shy away from harsh realities - e.g. main characters die and the good guys have bad times (they get screwed over, in-agency politics, marriages go sour, loved-ones die, etc.). The good guys don't always win in every situation.
For instance, when you watch the 3rd season, defusion, you'll watch one of the harshest scenes/happenings I've even seen. It happens in episode 17, in a stark, lifeless train yard - and then the episode ends. If you have to watch the next epsiode a week later, it makes event even more harsh: you'll wonder for a week how it could actually have happened and what the repercussions are.
(Luckily I watched the box set, so I didn't have to wait a week

. Nonetheless, the event surprised me: I kept expecting it to be called off at the last minute.)
Sorry if this teases you, but for me it just reinforces why this is such a good series!
Oh, and 4th season... well, it's really made me look forward to the next season!