I'm in the West Los Angeles area at UCLA near Westwood and I noticed it around 10am this morning. Must have hit the switch at that point since I use my phone a lot and didn't notice it before that time. Haven't ran speed tests but it is much faster on YouTube, downloading apps, FB app, Songkick app. The browsing didn't seem that much faster but I think I'll have to go to each page first until the info is in the cache and then revisit to see a difference. I'm excited after months of waiting!