The Franklin is Class III, maybe Class III+ (which can be, yes, portaged easily), except for a handful of Class V to Class V+/VI drops.
Some of these un-runnable drops are a bit involved in their portages, with ropes, ledges, cliffs and scrambling through brush. These are the infamous Churn, Thunderush, Cauldron, and Pig's Trough. Even the less involved portages like Log Jam, Nasty Notch, upper Coruscades, Ole' Three Tiers, and Big Falls look like a pain for anybody with Class III skills and a hard-shell kayak or big, 12 foot+ raft.
Anyway there's really very little Class IV (and what there is seems highly dependent on water level), the kind of stuff that makes you feel like a wussy for not running it, but when you do, you swim and lose a paddle, or a boa,t or skin off your knuckles. I don't like to run Class IV with a week's worth of camping gear and food, so I'd portage that, too, if there was a bunch on the Franklin, but there isn't. Just miles and miles of great Class II and III and moving water though pretty gorges.
What tickles you, the packrafter, there on the Franklin -- the way walking miles on sore feet and then getting into your boat to paddle tickles you, like you're getting away with something in a clever way -- is that the terrifying cascades and waterfalls of the Franklin can be portaged.
In a weird way -- like the way it's summer down there when it's winter up here, and their swans are black and ours are white, and the sun goes across the sky from right to left there instead of left to right here -- on this river, what tickles you, the packrafter, is not getting in your boat, but getting out of it.
Here's how we rig for that: