commuting between cities

[turnipmonster]

very good chance I am going to be working 4 days/week in dc and living in nyc, commuting via amtrak. I've never done anything like this before, and would love to get some thoughts by people that have experience commuting weekly.

my case is probably a little different than most people's because I'll have to rent a room myself, it's not like a lot of consulting gigs where everything is paid for.