According to the brochures an AW.149 can carry 16 fully armed or 19 lightly armed troops v an S70i's 11 Troops + 2 Gunner/Crew Chief. Cabin volume is identical.
AW149 cabin is wider and shorter than S-70. As a result, in the former, the pilots seats backreasts are pratically in-line with the gunner window frame edge. I wonder if and to what extent it will affect its operation.