1) if i remember correctly some people were still complaining about warping opponents. personally i dont experience any lag with antiradar.
2) it was said the flag arrow sometimes points to a totally different direction than the direction where the enemy really is located. personally i dont think i've experienced such thing so far.
3) it was mentioned sometimes people dont get hit by long-distance seekers when they get hit far offscreen. i tested that with someone and we couldn't verify that problem - the hits worked fine.
4) it was also said sometimes people dont get hit when they respawn after using a warp and get shot instantly. we also tested that and couldn't verify the problem - the hits worked fine. dunno if thats different for other people with higher ping.