My struggle with Reavers is that there are allies who are just flat out better at the same job. Most of the Stormcast shooting is more powerful for a similar points cost.
Vanguard Raptors w/ Hurricane Crossbows 140 pts: nearly the same number of attacks (compared to Reaver volley) but at 18".
Judicators 160 pts: 24" ranged shooting with rend and bonuses to hit against Chaos
Castigators 160 (for 6): access to -2 rend and the option to improve accuracy
Celstar Ballista 100pts: No need to explain. They're just great.
I LOVE the models, but when I'm looking through a purely competitive lens, it's hard to make a great case for them, outside of them having more bodies or being marginally quicker than the above lists units.