I guess I'm talking about connectivity for outlying urban and inner suburban neighborhoods ("the subway") more than regional rail systems like LIRR or, in Chicago's case, Metra.
It may actually be a good strategy to live even further from the city if it lets you switch from a crowded urban transit system to a more spacious suburban one.
Commuter rail tends to be more expensive than heavy rail too.
It's a good question though (let's put aside costs for now): How much more time would you be willing to spend on commuter rail over heavy rail if it means getting a seat? I'm not sure. I think I'd rather be seated for 40 minutes than standing for thirty, but at an hour, I might just prefer the shorter trip. You can still easily listen to podcasts on crowded heavy rail, or get good at holding a Kindle in one hand.
It may actually be a good strategy to live even further from the city if it lets you switch from a crowded urban transit system to a more spacious suburban one.