Between 1100 and about 1400 I can barely do anything with my phone.
Email, messages, Facebook IM etc... it will work fine throughout the morning and afternoon while at my desk at work but for that three hour period its a nightmare. It shouldn't matter indoors vs outdoors as it works fine any other time except for the stated 3 hour period. As far as WIFI goes.....NO. It's work WIFI and I do not want my phone on the work WIFI, I'm paying for cellular service and expect to be able to use it.