Hagar is a weird weapon, but as mudkip has been recently abusing me with, it can force your opponent up and get them to hover in the air while you deal massive damage to them. It's kind of like the lg, but executed differently, and only a few cm above ground at the most. It's pretty powerful... most of us just don't know how to use it appropriately yet.
As for the HLAC... I really was going to leave this alone and let it die out, but... yeah. I know people who like jet packs. I know people who like hook. I know people who like minsta. Just because some people like something doesn't mean it belongs in core gameplay (usually for balance reasons). I'm going to say that cheesey line every other person says when someone talks about a change they don't particularly like. "Make it into a mutator." The HLAC, when first introduced, pushed people back into walls, and killed them. That's pretty much all that ever happened with that weapon. You couldn't move because you were being pushed by all the lasers hitting you constantly. The seeker performed a similar function on maps without walls. The one CTF map with chunks of earth floating in space comes to mind. Tag your target repeatedly and watch the gazillion rockets race around the map following them. If I remember correctly, getting tagged twice was essentially death for anyone not stacked above 100/100.