TIM seems to have good LTE coverage, at least in bigger cities.

In UK right now and noticing Vodafone data is working again. Wonder if issues I had 2 months ago were issues technical issues or something blocking data users from TMO-US. For now though it seems to be working. Will edit wiki if it continues to work through the week.

I haven't been able to find this answer anywhere yet. If I buy a Simple Choice mobile internet plan 1GB, can I put the SIM in an old iPhone I want to use w/o calling or will it require a corresponding voice plan to work?

I was in the UK (London and SE) from 6 to 10 December and used Vodafone for data more than half the time.

The data only plan works in my android phablet (domestic & international) and I'm told also works in a iPhone 5s.

Made that mistake once, never again.

I was told at the Vodafone store near the French border that the activation will take up to three hours. By that time, we were a few hundred kilometers away. One phone worked like a charm, but the other would not connect to the data network. It wasn't the SIM, because when switched, it worked in the other phone. The phones are identical and all the settings were the same.

The Vodafone store at our next stop refused to help because they didn't sell us the SIM card.

Next time, I'll chose a different carrier in Italy.

Interesting link here. Vodafone is going to use T-Mobile US as an MVNO for their global customers (read they won't offer service to consumer in the US - but to large global enterprise customers)

With Verizon cutting all ties on Verizon Wireless to Prior parent Vodafone guess this makes sense.

Hopefully we will see more robust roaming interconnect for better data performance when roaming on Vodafone networks. (Better backhaul and lower latency would mean even speed restricted 128Kb can be better)

http://www.engadget.com/2014/12/12/v...ed-by-t-mobil/

Japan, Singapore, and Thailand
 

Japan
-Inside Narita airport my phone automatically selected and connected to Softbank. HSPA service in most areas with some spots where it falls back to UMTS.

Singapore
-Inside Changi airport my phone automatically selected and connected to M1. Display was SGP-M1. HSPA+ service.

Thailand
-Inside the Bangkok airport BKK my phone automatically selected and connected to DTAC. HSPA service.
-Inside the Phuket airport my phone automatically selected and connected to DTAC. HSPA+ service.
-Once in Patong the display changed to dtacTriNet HSPA+

In all the locations above, SMS messages were delivered and sent without delay. Data worked, if slowly. My phone is a Nexus 5 US model running Lollipop.

Wiki updated by moving Singapore M1 out of problem networks.

I was the one who added the notes about SMS issues with M1 Singapore into the wiki. I appreciate your update -- great news if this has truly been fixed... you didn't have to manually enter an SMSC into your Nexus 5?

Guess I'll find out later this month.

Noted; about a month ago it was problematic in the UK and Germany (connection but no data bearer)

Coverage in China
 

i am also considering switching from Att to take advantage of this TM plan with unlimited international data roaming. I know this might already have been mentioned in previous posts but just wanted to see if anyone has the latest update regarding data coverage (network/city) and speed experienced in China.

I just got back from London and used Three most of the time and it was fine. What I forgot was that there is no reception on the Underground whilst underground on the trains. I know that Virgin has wifi in the stations and on the platforms and after doing a little research, now that I'm home, I found this,
"If you're an active EE, T-Mobile or Orange mobile customer you can access unlimited WiFi on the London Underground.
Just Text EEWIFI to 9527 and we’ll send you a password to access the service when you next go on the Underground." http://ee.co.uk/help/add-ons-benefit...he-underground

I wonder if a simple global user would be eligible, does anyone know? Not that it would do any good while actually on the trains but it would be nice to have on the platforms, especially if it's free.

That's for T-Mobile UK users.

China Unicom does work fine and it will limit to 128Kb/sec which is OK for most use cases. It is APN tunnelled back to T-Mobile US so no filtering/firewall like you would get on a local SIM card. Paying for high speed will only benefit on China Unicom. If you roam on China Mobile it is 2G only (local Chinese 3G/4G tech used for non 2G when on China Mobile). China Unicom again is a proper UMTS/WCDMA network

Correct.

Also using TH GSM here in Phuket now.