As good as hacking is at the start, bullet time is waaaaaaay better if you're a pistol build--and those things are mutually exclusive since the Zetatech Sandevistan OS upgrades have no hacking ability. Don't make the mistake I did and put points in Int if you wanted that type of character... it's not just a gatekeeper in that case, it's a total waste of stat points which AFAIK are impossible to respec. For melee builds, the Berserk OS requires you to make the same tradeoff.
Body is a good stat overall, but if you sit down and read all the perks in the game it becomes obvious that Reflexes->Handguns is just insane. I overlooked Cool at first too, but with some investment the Cold Blood buff gets pretty crazy.
You sure you aren't hitting Caps Lock by accident? It works as a scan mode toggle, while Tab only scans as long as you hold it down.