Which is more valuable for a 1-skill crew: BIA or specific skills such as Recon, Smooth Ride, Snap Shot, Situational Awareness and Intuition?
Watching QB's recent video he recommends BIA first, but Skill recommends specific skills. So, I made a comparison on tanks.gg for the ELC EVEN 90, Progetto 46, Tiger II and Skorpion. Both options for all four had no equipment and premium consumables, with BIA on one tank and one skill per crew member on the other (used the skills listed above).
Conclusion seems to be that BIA wins in DPM and aim time/dispersion, but that Smooth Ride gives lower dispersion. BIA has better mobility in every category, but especially crews that can do both Recon and Situational Awareness have better view range. This was the most significant difference, coming in at about 3%.
So, what to do? I feel like generally speaking BIA is the better option, especially now that Sixth Sense is standard.
Source: https://www.reddit.com/r/WorldofTanks/comments/ytezps/bia_vs_specific_skillsperks/
