Pulling a digression from a somewhat related topic.
What's wrong with Ballistic Reinforced?
It's horribly inefficient in tonnage.
That's kinda my point. I'd reserve "really bad" for something like Heat Dissipating Armor. BRA isn't mind blowing, but it does exactly what it says on the box by blunting 2 of the 3 weapon "food groups". It also lacks any overt drawback like Reflective or Reactive. So for a 25% reduction in points per ton over standard armor, that seems pretty fair. My only complaints would be taking up 10 crit slots and not protecting against armor piercing effects like the Hardened Armor it's derived from.
Just to be clear, I was explaining why other people think BRA is bad. I think it is completely reasonable in isolation and only made somewhat unfavorable because the people I play with favor energy-heavy setups. I assume (given how much people here complain about flashbulbs) that holds reasonably true across the board, but I'm not sure. Also (IS) ferro costs 14 crits, so you're actually getting something back by going with BRA instead.
Crit-protection would take it from being an alternative armor type to being more like the next-generation standard, because that would stop the LB-X TAC-fishing cold. I'm not sure if that's good direction for the game or not but I play mostly MM and think it would be, because damn will people toss pellets by the dozens when they don't need to toss dice by the dozens to resolve hit locations.
LB-X autocannons are one of the more popular ballistic weapons (aside from Gauss). The usual response against BRA, when I was experimenting with it, is "More Dakka!", specifically cluster rounds. Which made the BRA, effectively, a heavier version of ERA.
That "minimum 1 damage per attack" clause on the "food group armors" can be downright painful...
Sure, it leaves LB-X's cluster rounds in place, in terms of damage and TAC-fishing. But you're getting the essential benefit of hardened armor (except TAC-protection) against both ballistic and missile weapons otherwise. It out-performs hardened against five point clusters (pic related) or anything with favorable rounding to a less degree. Unlike hardened, you can mount it on omnimechs and you're not losing speed or taking a PSR penalty by mounting it. That BRA has counters doesn't make it bad, just not an out-and-out superior form of armor to replace standard/ferro in all circumstances.
I personally don't think it is that good just because it leaves a unit, ton-for-ton, worse-off against energy weapons but that's a personal opinion formed on the basis of playing against guys who will flood the field with energy-heavy configurations.