Another thing that I like about fishing an intermediate head is that I can straight cast down river and can almost immediately fish.
About why sometimes the intermediate heads feel heavier is IMO depends on the rods. With me and my Beulah in particular, I felt it was a tad heavy, not a whole lot. So, I called Steve Godshall, and told him that I had an iShort 350 and it felt a bit heavy for my rod and he cut me his intermediate scandi/skagit hybrid head, 15cm shorter and 25 grain lighter. I know 25 grain isn't much but it feels really good, lighter, and matches my tempo; maybe just the taper. On the other hand, this rod depends on the length of the floating shooting head it will cast 330 and 360 just fine with the same tips.