I *drive* a decent chunk of it daily in the eveniongs anywhere from 3:30 - 7PM (sometimes in AM too, depending on traffic elsewhere). The bit I drive is Seven Fields to rt 8 ('cause 228 is a nightmare now).
It's never too fast, people actually go close to the speed limit or a little less (as opposed to 70 in a 45 like some roads). That part the speed limit is between 35 and 45. It's also never too busy or backed up, I'd say worst is around 4:30-5:30. The only place that an actual line forms regularly is at a 3 way stop on... Babcock I think? But it's not a stressful intersection, people just take their time.
During the day, it's even emptier, but no faster.
I've never biked it, but there's a motorist's POV (one who bikes, but still). I'd totally do it... in fact I'm planning on it when the leaves start to turn.