Once you have a line, commuting is slightly easier. However you will be giving up access to some of the "easy" flying and much of the very lucrative open time, if you're not close enough to the airport to get there quickly. You can do ok commuting and still get your 15-17 days off, but it'll just be harder to pick up that easy extra 10-20% that someone in base can generally grab out of open time. Like those single leg trips that contractually require 2 days either starting or ending (or both) with deadhead legs, so you're getting paid 10 TFP for a single leg and you can be back home less than 12 hrs after going to work. Hard to get those if you're not living in base.

I will say that if you need to be convinced that a 121 job is a good move for you, then maybe it's not... If you think your current job has less job security then you need to be living well under your income and piling up cash for when times are tough. I know lots of people who make $300k/year in industries that might evaporate tomorrow. They live off $100k and bank the other $200k against the time when they have to switch career fields because their previous career field simply doesn't exist anywhere anymore. That's smart no matter what job you have but it's really important in the flying business because we're darn nearly the proverbial canary in a coal mine. When the economy tanks or something significant happens (anyone willing to bet automation won't replace FOs in the next 20 years?), professional pilots tend to get hit early and hard (sts). If you're not seriously planning ahead for the next downturn then your backup plan isn't really much more than the local soup kitchen.