Pyrhic, you really can’t compare a tank with 4 battles to a tank with almost 400, it just isn’t useful.
As for how it feels, people have measured the effects of BiA and Ventilation using the reload time mods, and they reduce reload times by a fraction of a second. Consistent with only a couple percent worth of improvement.
When the new skills first came out, I experimented with them a lot on my Patton, which had Ventilation and BiA until I learned how small the bonus was. After removing both I don’t notice a thing. It’s not really possible to notice a less than 5% increase in tank stats, and one’s perception is just that.
Honestly, a lot of these news skills are completely useless, or nearly so, and exist only as gold sinks as people experiment with them (hence the extremely vague and unhelpful descriptions in-game). But some are extremely useful - like Sixth Sense.
Is Brothers in Arms really that useful for tanks (as opposed to artillery)? Well, the math and the in-game testing says it’s less than 3% improvement in tank stats (see the wiki for why that feeling is just a feeling). If I could use ONE crew member to achieve that, it would arguably be in consideration. But we’re forced to use EVERY crew member to get that less than 3% improvement. Perhaps others can justify it, but I cannot.
I’ve removed Ventilation and BiA from my Patton and never looked back.
Current skill set up is:
Commander: Sixth Sense 100%, Camouflage 100%, Repair 80%
Gunner: Snap Shot 100%, Camouflage 100%, Repair 80%
Driver: Offroad Driving 100%, Camouflage 100%, Repair 80%
Radioman: Camouflage 100%, Repair 100%, Situational Awareness 80%
Loader: Camouflage 100%, Safe Stowage 100%, Repair 80%
Equipment:
Binoculars
Enhanced Gun Laying Drive
Vertical Stabilizer
I couldn’t give up any of these, realistically, for a 4.4% increase in tank stats (actually a decrease in many areas, since many useful enhancements would be replaced).
Now if I had played the tank for some 1000 battles (as opposed to only 465) and had four skills to choose from … nah, still wouldn’t take BiA.
I don’t play artillery anymore - not for some time, but the people who do all say one thing: take anything that improves aim time. Repair is also important if you get splashed during counter-battery, that one I know from my own experience, but on artillery Brothers in Arms is a good idea because, well, where else are you going to get increases in aim time? Even 2.4% is better than nothing.
Same goes for Snap Shot, it’s not just turret rotation, it’s all gun movement.
On a small artillery like a Hummel or GW Panther, camouflage is also very useful. But as you move up in tier, and arty gets bigger, their camouflage rating drops to almost nonexistent, so you need not bother with camouflage anymore (or the net).
Beyond that I would ask dedicated artillery players who have a lot of experience since 7.2 came out.