There are a ton of mechanics in the game I still get mad at, on both sides, over this game I seem to still be obsessed with. In MOST cases, I may call it BS, but I least I can make some kind of comeback in my mind as to some balancing around it. Going to focus on xeno side as my counter complaint comes from a marine side action.
White flame OB will kill just about any xenos on contact in a huge range. Yea but there was a warning on general location, and if really stuck you could try running to the marines and pray to god they didn't fire it danger close. Even if fired directly on top of you, there SHOULD be enough time to get out of most OB strikes.
Shotgun juggling means solo marines can kill many xenos. Sure but to do that in the first place they have to be at point blank range, and you can see if they have a shotgun in their hands. Xenos can see through walls so in just about any case you at least had a warning your death was coming if you were to go close to them.
Stims marines can outrun and gun down the xenos. Yes but stims have been dialed back so they now appear only later in the game allowing combat without them. Only in combination with other cheap tactics like said shotgun juggling does it become really a noticable problem. Otherwise they tend to just push harder. It is still dangerous for stimmed marines to run straight into the xeno line. Sometimes their sense of power can make them overconfident too.
Grenade jugging...is painful. At least it requires some skill in timing along with xenos being in the right position at the right timing. I feel like with the number of times I have been juggled it might be too easy but at the same time I have never tried it myself. If they are not gods at it, there IS a window you can notice and avoid it, or so it seems. There was one god who managed to get a grenade behind me and immediately explode it so my stun body was in front of the marines, but it was so well executed I wasn't even mad.
Finally onto the topic: SADAR. I got nothing. I can be a defender with crest down, poke my head out the door, see SADAR was one tile below where I could see, and now I am dead. Same with many other xeno classes. Usually just a SADAR rocket followed by a few bullets onto the now destroyed area with my stunned body sitting in the open. One shot one kill.
The tip of the round wants you to reflect on why you died sometimes and how to improve. In those circumstances all I got is don't fight marines. There could be a SADAR that will one shot you without anything you can do about it.
edit: died to sadar again as prae, yep, I might be done with this game for a while