Project Fi is more expensive than the T-Mobile $30 plan but it does have some significant advantages. You can use Sprint's entire network as well, you get unlimited international roaming (which is a godsend if you make occasional overseas trips), and you can use the native voice network for calling and SMS which gives much better coverage and reliability especially in rural areas or crowded places like stadiums.
I'm just starting my second month with Fi. I also had the T-Mo $30 plan and thought it might come out more expensive.
I've come out actually slightly cheaper than the T-Mo plan. WIFI seems to be pretty ubiquitous where I go because I only used ~ 300MB of data last month.
Usually I use ~ 2GB per month. The one big change I did at the starting of the month was set my podcast streaming apps to sync on WIFI. That's about half of my monthly data right there.
I'm currently on t-mobile, so the project fi network is at least as good as what I have now. The pay-as-you-go data plan is also going to work out to be cheaper for me - I currently have the 3 gig plan with rollover, because every few months I end up in a hotel with bad internet and really need more than a gig of data. I'm definitely paying every month for a service I only occasionally need.
I wonder what it will be like, psychologically, when I'm paying by the megabyte for data. Right now, I know I've already paid, so I just stream stuff. Under project fi pricing, my total cost per month will go down, but it will also be metered- I can have it go way down if I'm frugal. Not sure if I'll download that audio book on LTE if I know I'm going to end up paying an extra buck for it. I mean: it's just a buck, but still. Interesting to see where I land.
For me international roaming is the main advantage (although I usually buy local SIM cards if I'm in another country for an extended duration). T-Mobile coverage works very well where I live (Bay Area). If I'd need better coverage for rural areas I'd probably sign up at a Verizon MVNO such as Straight Talk ($45 for 5GB).
Sprint's network is pretty bogus, though. For $45 a month I use Cricket, where I get 5GB of bandwidth (10GB for $55, it's a recurring promotion) on AT&T.
