It's wild how much they're charging for the scooters. $1 unlock + $.35/min ride time. Back in 2013, you could rent an entire Smart Fortwo from car2go for essentially the same price!
It makes sense when you compare it to other transportation options: if the bus costs $2.75, and a lyft ride costs $20, getting there by scooter for $7 seems reasonable.
If a bus costs me $2.75, I'm almost certainly not paying $7 for a 20 minute scooter ride. The bus will get me there in ~the same amount of time, 98% of Seattle buses are not crowded, and they don't subject me to the risk of a scooter-car collision, which would quickly be followed by an unprotected head-pavement collision.
Whatever works for you! I'm sure it depends a lot on the part of town you live in. For me, the scooter trip to work is only 10 minutes, while the bus trip - including the walk to the departure stop, the wait for the bus, and the walk from the destination stop - takes more like 25.
If I'm in a hurry, then, the scooter has a clear advantage; it's not competing with the bus, it's competing with Lyft, and it's both cheaper and lots more fun.
Most of the time I use scooters not to commute to work, but to run errands around the neighborhood. Then again the scooter is not competing with the bus - it's competing with my own feet! I do a lot of walking, but it can be really nice to have a motor help you carry the groceries home, or just get you where you're going quickly when time is short.