I do think that osb is fine on a roof deck too, I just think that plywood is a little safer if things go wrong. I think that osb is fine for subflooring in many applications, as the article points out. Engineered Wood I-joists are great. Stronger, straighter, more stable, stiffer, etc. than sawn lumber. And you can cut out sections of the web for ductwork and plumbing.
Manufacturers provide literature that spells out the acceptable sizes and location of the cutouts.
The I-joists are stronger and stiffer, so the size also can be different. Span, species, loads, etc. You should feel comfortable with this product.