Well, with me its a coin toss, I've had many days where the home internet was unusable, and the cafe's ok for my needs (mostly just ssh) - except when a bunch of teens come in and open up youtube simultaneously. It's too noisy for hangouts though, so I only use it at a point in the day when calls are unlikely.

I found this to be true as well. You should really look into a mifi. At ~50 bucks a month it is well worth the investment, especially if you have a bus commute or like working in coffee shops, etc as you mentioned.

I tether to my phone but my favorite coffee shop doesn't get good cell reception for me either :/