I made a similar thread on Splash forum, but no answer
So kinda copy-paste here:

After getting to 20 my medic (with splash of soldier) I made new character, and speced him for Operative. I really like it, and after ~10 levels of multi Im getting to feel how to play that class (ET/QW lover here, but still it's kinda different in Brink). So I made a little gameplay that shows me playing, and I would be really grateful for pointing my mistakes, or for some tips how to be better with this class.

Cheers and thnx in advance!

Clip: http://www.youtube.com/watch?v=UQbC0DvJsrA

I'm going to be editing this post as I watch.

First off, Comms Hack is probably more useful than Hack Turret, unless the people you tend to play against are especially turret-happy. Even if they are turret happy the turrets end up being the wrong way and useless to your team and the time spent hacking them should probably just be spent disabling them. On the other hand, Comms Hack gives you a massive advantage when trying those long hack objectives because you can see when an enemy is getting near and from which direction.

At around 1:17 when you sneak around the back... for me, personally, that would've been a fantastic Sticky Bomb opportunity. They are lethal, and do a lot of damage to groups. Those guys are clearly about to enter that enclosed space, and they weren't looking at you so your disguise being broken by throwing it would not have done any harm. You were successful, so I dont think what you chose to do was any wrong, but... you asked for suggestions. I bring it up because at roughly 1:59 that was probably a worse use for the sticky, to just get one guy.

Really good move at 7:08, keep thinking like that and you're on to a winner.

P.S. Stop wasting ammo on incapped dudes. Especially your silenced Seagle (which was interesting to see the same way I set it up) because you could really need that at some point. Just knife them or leave them. The only time I'd ever shoot at a downed enemy is if it's a Medic and I'm worried they might have self revive. Every other time it's probably better just to 1) save ammo 2) move on. I only ever even knife them if I think there's a chance they'll get revived by someone soon (which I would figure out from Comms Hack)

I watched your video not bad you play the class well i would just recommend comms hack.

Thnx for advices, will get Comm Hack (and stop wasting ammo ).

As an Op, you should try to keep either Sticky Grenade or Caltrops should be on cooldown at all times. It probably isn't a bad idea to leave one pip in reserve for emergency frags. (Depending on the situation, and if you have a Supply CP)

Turret Hack has it's uses, especially if you want to disable a turret without shooting. I would recommend staying away from Remote Control, it's not worth you standing still to borrow a stationary turret.

Really solid gameplay on your part. Like people said, go easy on the killing incapacitated guys. Once you hit rank 4, keep your eyes on Medics and never melee a downed Op. At rank 5 feel free to waste anyone with Downed Fire, as it only takes 2 shots from the Sea Eagle.

Keep up the good work.