The mere fact that it is a call-in unit not having a requisite building is a huge strength. It's also slightly more survivable since it doesn't decrew with only 1 man left.
Its only a bit more survivable. Crew s8zes are identical.
I choose 82mm because its cheaper and non-doctrinal and gets to vet1 much faster. Then you'll hear some "enemy infantry down"s and "we fckd up that squad"s after like 50% of the time you use precision strike.