I was very interested until I got to the part of no LTE support. That's a deal breaker for me. I had a Samsung S3 that I busted and opted for the Samsung S3 Mini at one point, and the lack of LTE cost me dearly. I literally couldn't browse the internet unless I was on Wifi.
I'm curious - isn't 3G the fallback speed when LTE is unavailable or when your phone doesn't have LTE support? Or is LTE a separate band that may exist without 3G at all in some regions?
My wife's Nexus 4 (3G) seems to get internet just as often and approximately as fast as my Galaxy Nexus (LTE). Then again I don't stream videos that often over data networks, because it sucks to hit the limit and get choked back to 2G on T-Mo.
LTE has one killer momentum - extremely low latency. I have to go back (temporarily) to a phone without LTE support and it's a pain, actually.
Edit: I'm from Latvia. We currently have Band 3 only LTE with Band 7 and Band 20 coming next year. And even though actual speeds are not South-Korea-like, 20Mbps+ is a norm.