[HD2 Android Q&A, Help & Troubleshooting and Genera] Darnell_Chat_TN:
Just tested ping response rates for north-america.pool.ntp.org versus lbs.geo.t-mobile.com.

D:\Program Files (x86)\Android\android-sdk-windows\platform-tools>adb shell ping
north-america.pool.ntp.org
PING north-america.pool.ntp.org (149.20.68.17) 56(84) bytes of data.
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=1 ttl=44 time=257 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=2 ttl=44 time=255 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=3 ttl=44 time=244 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=4 ttl=44 time=173 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=5 ttl=44 time=211 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=6 ttl=44 time=162 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=7 ttl=44 time=149 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=8 ttl=44 time=218 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=9 ttl=44 time=226 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=10 ttl=44 time=175 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=11 ttl=44 time=154 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=12 ttl=44 time=162 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=13 ttl=44 time=150 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=14 ttl=44 time=179 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=15 ttl=44 time=158 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=16 ttl=44 time=166 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=17 ttl=44 time=165 ms
64 bytes from pool-test.ntp.org (149.20.68.17): icmp_seq=18 ttl=44 time=154 ms
^C
D:\Program Files (x86)\Android\android-sdk-windows\platform-tools>adb shell ping
lbs.geo.t-mobile.com
PING lbs.geo.t-mobile.com (10.176.29.225) 56(84) bytes of data.
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=1 ttl=241 tim
e=155 ms
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=2 ttl=241 tim
e=135 ms
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=3 ttl=241 tim
e=144 ms
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=4 ttl=241 tim
e=143 ms
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=5 ttl=241 tim
e=142 ms
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=6 ttl=241 tim
e=151 ms
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=7 ttl=241 tim
e=141 ms
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=8 ttl=241 tim
e=149 ms
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=9 ttl=241 tim
e=148 ms
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=10 ttl=241 ti
me=148 ms
64 bytes from 225.29.176.10.in-addr.arpa (10.176.29.225): icmp_seq=11 ttl=241 ti
me=147 ms
^C
D:\Program Files (x86)\Android\android-sdk-windows\platform-tools>

lbs.geo.t-mobile.com was responding at a range of 135-155ms, while north-america.pool.ntp.org varied from 149-257ms.

So lbs.geo.t-mobile.com being on T-Mobile USA's network does seem to consistently respond faster. I thought about changing my own setting, but the difference is only about 0.1 second (100ms). So I doubt that 0.1 second is very noticable. It appears to be a very minor factor in my overall lock time given I am in the US. The redunancy of north-america.pool.ntp.org at the cost of 0.1 second seems better than relying soley on T-Mobile's server. And this all only comes into play when the A-GPS data is refreshed right?

I think the value may have more of an impact on people outside of the USA. But having the setting within nation (and the actual carrier's server does help a little) and a utility to download the A-GPS data (like GPS Status & Toolbox) probably is best.