So let's discuss stormboyz.
The way the meta is right now they are pretty important and I don't see that changing much in the near future. The situation currently is that it feels like you're wasting an elite slot on a unit that you shouldn't need to.
That's clearly not happening however, but I just feel as though stormboyz themselves are kind of lacklustre for elites. Yes, they are only 2 point elites, so I'm not expecting them to be amazing, but the way they currently are, they aren't much better than an ASM squad (especially with power swords) and that's a problem. Part of the problem is how squishy they are...they melt surprisingly quickly and you need to sacrifice at least one to get some decent damage off. I feel like their jump ability in particular could use some work - as it stands it's basically a one-way trip for them if they are jumping into battle, because they aren't jumping out again before they die. Having a reasonably long cooldown on ASM jumps is fine - they are line units. Stormboyz are not line units - they are elites, and so should be better at surviving.
My suggested change is for stormboyz to have two jumps available off a charge before needing to cool down to jump again. This will allow them to jump into battle, disrupt, do some damage, and jump out again. Or jump in, harass a resource point, and jump out again. The cooldown on the jump ability could even be increased to compensate honestly - I think that would be a fair trade in order for them to be able to jump twice off a single charge.