Success, mostly
Cool, please update. This would be handy for travel out of the US.
Cool, please update. This would be handy for travel out of the US.
OK, I am back from my trip and had a fairly successful experience. Upon arriving in Edinburgh, I found a Vodaphone shop near the train station and picked up a one-month micro SIM. I was expecting to get 2 GB of data for about £15, but they had a special -- unlimited data for just £10. You also got a certain number of calls/minutes and texts, but I wasn't planning on using those much.
My phone had a persistent notification about a non-Verizon SIM in the pull-down, but otherwise it worked fine within the limitations of the Vodaphone network. We were traveling into some remote parts of Scotland and often were out of data range, but I had wireless at our cottage and used that to download offline maps in Google Maps for the places we were going*. For the most part, outside the metro areas, we were out of range more often than not, but that's rural Scotland for you. All my apps worked just fine as if nothing had changed. (One thing to watch out for is if you have 2-step verification on Google or other apps, and it sends a text message with a number, because that text won't show up until you put your own SIM back in.)
We did have a problem making a phone call at one point when we had car trouble near one of the touristy castles. I couldn't make a phone call; automated help line said that I still had 100 minutes remaining but no 'credit'; the Vodaphone help line cost 26 p just to talk to someone for assistance, so I couldn't call them without credit; and when I tried adding credit, it wouldn't accept my Master Card. I thought maybe it was a roaming issue, but when I tried making a call in Edinburgh a week later, I got the same message. I meant to ask/complain to Vodaphone (we would have been in serious trouble if we hadn't been near a pay phone), but didn't have the time.
So in short, I got unlimited data on my Galaxy S4 for a month in the UK for about $15 by swapping in a SIM that I picked up in a store. I had no trouble with Verizon, and nothing had to be unlocked or rooted. My fiance went to a mall kiosk before we left and got her HTC S unlocked for $25, and had the same experience (including the trouble with the Vodaphone calling plan -- if we had to do it over, she would have gone with a different company, like O2 or Orange).
* On the day before out last big outing, a major update to the Google Maps app caused the menu button on my phone to stop working (and it still isn't), preventing me from getting to the download offline maps feature. Grr.