I have had my BlackBerry on Simple Mobile (an MVNO of T-Mobile) for a long while and have been happy with it. They offer true BlackBerry BIS at a significant savings over post pay plans.
For 4g coverage, the advantage is more 4g bandwidth before you are subject to throttling. T-Mo's $50 plan subjects you to throttling at 500 meg, whereas the same 50 bucks at Simple gives you 3 gig of 4g before subjected to throttling. They also offer a 1 gig 4g, otherwise unlimited plan for $40.
If you have a Simple Mobile micro Sim and want to put your 521 on Simple Mobile, I can tell you it works. I have had mine on for a few days. No problems. Good speed on 4g and MMS messages send and receive no problem.
It's up to you, but if you want to, here is the protocol, FYI. I don't work for Simple Mobile, T-Mobile or any wireless carrier and I hold no stock or interest in any. Just offering this as what I did because it worked for me. Good luck.
Here are the programming instructions for using the 521 on Simple Mobile.
Go to SETTINGS
Open CELLULAR
Make sure SIMPLE MOBILE is the network selection, if not it needs to be added. You don't want T-Mobile
Go to SETTINGS
Open ACCESS POINT
Make sure SIMPLE MOBLE is active (initially, it should NOT be there - you have to add it - so ADD IT! )
Press ADD
Name it whatever you want, I named mine SIMPLE MOBILE
Once added make sure it is the ACTIVE NETWORK
Program over the air Internet and MMS for internet and picture message send and receive
Go to SETTINGS - ACCESS POINT
HOLD YOUR FINGER ON THE SIMPLE MOBILE YOU JUST ADDED
A drop down menu will appear - Choose EDIT APN
INTERNET SETTINGS
Access point name - simple (all lower case!)
username - leave blank
password - leave blank
proxy port - leave blank (try 80 if you have to put in a number but best to leave it blank)
Proxy address - leave blank (put in one dot (.) if you have to but remove it later after saving
Network type - should be IPv4 and should be in there already
authentication type - none
MMS APN
mms apn - simple (all lower case)
username - blank
password - blank
proxy address - blank
proxy port - blank
mmsc address - http://smpl.mms.msg.eng.t-mobile.com/mms/wapenc
network type - ipv4
authentication type - none
For 4g coverage, the advantage is more 4g bandwidth before you are subject to throttling. T-Mo's $50 plan subjects you to throttling at 500 meg, whereas the same 50 bucks at Simple gives you 3 gig of 4g before subjected to throttling. They also offer a 1 gig 4g, otherwise unlimited plan for $40.
If you have a Simple Mobile micro Sim and want to put your 521 on Simple Mobile, I can tell you it works. I have had mine on for a few days. No problems. Good speed on 4g and MMS messages send and receive no problem.
It's up to you, but if you want to, here is the protocol, FYI. I don't work for Simple Mobile, T-Mobile or any wireless carrier and I hold no stock or interest in any. Just offering this as what I did because it worked for me. Good luck.
Here are the programming instructions for using the 521 on Simple Mobile.
Go to SETTINGS
Open CELLULAR
Make sure SIMPLE MOBILE is the network selection, if not it needs to be added. You don't want T-Mobile
Go to SETTINGS
Open ACCESS POINT
Make sure SIMPLE MOBLE is active (initially, it should NOT be there - you have to add it - so ADD IT! )
Press ADD
Name it whatever you want, I named mine SIMPLE MOBILE
Once added make sure it is the ACTIVE NETWORK
Program over the air Internet and MMS for internet and picture message send and receive
Go to SETTINGS - ACCESS POINT
HOLD YOUR FINGER ON THE SIMPLE MOBILE YOU JUST ADDED
A drop down menu will appear - Choose EDIT APN
INTERNET SETTINGS
Access point name - simple (all lower case!)
username - leave blank
password - leave blank
proxy port - leave blank (try 80 if you have to put in a number but best to leave it blank)
Proxy address - leave blank (put in one dot (.) if you have to but remove it later after saving
Network type - should be IPv4 and should be in there already
authentication type - none
MMS APN
mms apn - simple (all lower case)
username - blank
password - blank
proxy address - blank
proxy port - blank
mmsc address - http://smpl.mms.msg.eng.t-mobile.com/mms/wapenc
network type - ipv4
authentication type - none