Hmmm...ok, I'm not really sure what to do. So I'm the guy who went into the Apple store on Sunday and got a brand new 6 due to the issues being described. To answer a question someone asked, yes - the Apple tech did run some tests. She went through everything very quickly and her diagnosis was "it could be the SIM reader". It sounded like she didn't find a smoking gun showing it was SIM related, but she didn't fight giving me a new phone...she actually suggested it without me asking.
So, back to me not being sure what to do. I had a full day under my belt of testing the phone at work, and I will say that overall my signal was better than my original 6. However, the only call I had today I dropped after about 5 minutes (just sitting at my desk). Also, the signal strength still isn't where it needs to be based on direct comparisons of others' Verizon iPhone 5 and 5s's. Also, I'm going to do a few more Speedtests tomorrow but the ones I did today were very poor (~1 Mbps on 2 bars of LTE...).
Now the big thorn that just got stuck into this situation for me is wifi... I just had an issue where a Youtube video was freezing up on me at home, so I quickly ran a Speedtest on my phone and my MBP at the same time. My MBP returned 2 consecutive Speedtests around 60 Mbps while the 2 consecutive iPhone 6 Speedtests all registered LESS than 1.0 Mbps. I rebooted the iPhone and it jumped back up where it should be to 60 Mbps.
I have a strong feeling there are major connectivity issues with the 6's, so I have to make a decision soon before my 14 day return policy at Verizon is up. Decisions, decisions...