I decided to stay with MetroPCS.
I get unlimited talk/text/web at 3G speeds for $50/month flat (tax included). The SIMPle Mobile salesman says all I can get from SIM here is 3G.
MetroPCS will give me 4G for $60/month or 4G with a 1Gig stream then throttle back for $50/month.
I am happy with 3G speeds. I work out of my home where there are a few computers on DSL and they have better speakers than my phone, so streaming in 4G is not an issue with me. I have an iPod with 10,000 tunes on it so when riding in the car I'm entertained by my iPod.
Since nobody can give me any clear cut advantage of going with SIMple Mobile, I'll stick with MetroPCS. I'm actually satisfied with the service, and happy with the flat rate.