I agree. As I have a lvl 40 spine/ninj stalker, and I have a lvl 43 claws/regen scrapper. All I have to do with my scrapper, is wait for the crouch of the AS, cover my heal, and as soon as I get the AS, I pop a heal, and then it is death to the stalker.
As for playing the stalker, I have hide, stealth, and invis. If there is a defender around, I have to run up with invis on since they can see you a mile away even with hide and stealth. Now we all know you can't attack in invis, so how do we kill then.......Well, bind to a key where invis goes to stealth, and then have the same key start AS. Therefore, as you are getting to your target, hit BU. Then when you are next to him, double click your bind. This should put you from invis to stealth and in AS mode in less then a second. At this point, anyone with a CM cast on them from the defender, already saw you even when you were in invis. The problem is, they tend to freak and try and run. It is natural to try and get that safe distance back. Well, it is just too late. As they are running away, your AS should land at no matter what distance they gained from running. Well, how do we get the finishing blow? Simple. While you are crouched in AS mode, have a ranged attack qued up. Like my spines, I have impale qued while I am in the AS animation. Then wait and watch. The only other good tidbit I can say, put an extra range in your range attack.
Now as you noticed, I only talked about PvP. As for PvE, stalkers are becoming obsolete. Watch the next time a RSF is forming. Notice the corrs and brutes getting invites left and right. Then look to see all the lonely solo stalkers. It is sad to say, but after 40, there is really no point in continuing.
I know, I sound a bit one sided here, but if stalkers had a bit more hit points, then maybe they would be worth while. Yeah, the AS does great damage, but after that, you are screwed. Placate is not always that great. Once again PvE, it helps skim through the mobs, but it still takes too long. PvP, if you do hit me with placate, you will never damage me enough before it wears off. Anyhow, that was my two cents.