Just got a tip from a trusted source that NSN has a cluster of commercial 4x2 sites with closed loop MIMO at 2x20 MHz in North Dallas.That's pretty high performance stuff, essentially sites transmitting 4 Streams from the base station onto 2 receive paths on our devices. It's also Transmission Mode 4 (Closed Loop) when in low mobility, with higher chance of spatial multiplexing, and very high data rates.Not to mention that they've been running 20Mhz FDD LTE in North Dallas since last year, so really it's an unmatched setup by any standard, anywhere.NSN T-Mobile markets are Seattle, Portland, Dallas, Houston, San Antonio, Austin, Chicago, Detroit, Denver, Phoenix, Tucson, Tulsa, Oklahoma City, to name a few.For those lucky ones in those parts using an iPhone, the easy way to check the amount of Tx Antennas on the site is:1. Fire upby dialing2. Toggleto refresh3. Tap on4. Observe the "Typically, we will see 2 as a regular 2x2 MIMO setup, but if you see 4, that would indicate that your Service Cell Site has a 4x2 cluster. You should also notice more robust LTE signal, better average data rates, and more often seeing very high data rates than usual.