Originally Posted by
s0ssos
Tmobile international coverage is spotty and very slow (not even at the rate they advertise). It is almost always easier to just buy a SIM card there.
T-Mobile roams onto other carrier in MOST if not all countries they are the carriers with the best coverage (some exceptions). So coverage is controlled by the roaming network. If you think EVERYWHERE in the world you will get 4-5 bars ; keep dreaming. Even where I live Verizon whom everyone uses as a bencmark is the pits on signal strength (1 -2 bars and drops often). Not everywhere in the world will you get 3G/4G coverage and you will failback to 2G from a network point of view. As 2G fades away and spectrum reused for 3G/4G/LTE then you will see improvements.
Again none of the roaming networks coverage is controlled by T-Mobile just as it isn't controlled by AT&T or Verizon (or Sprint)
Now if you speak of data speeds, then YES the throttled "FREE" roaming will be slow if the roaming network has high latency back to T-Mobile. ALL data roaming on ANY NETWORK from ANY CARRIER means packets go back to your home carrier. That backhaul interconnect can sometimes as I said be latent or just not be the best (just as regular backhaul internet traffic can be). Meaning you may never burst to the 128Kps consistantly.
Suggest is pay for a high speed package or use a local SIM as you suggested. The fact that you get ANY data for free is entirely foreign to Verizon or AT&T in their plans. Get it's slow but for most of us it's MORE than usable