[Verizon Motorola Droid Turbo General] ChazzMatt:
I'm not going to totally disagree with you. I've never had no signal whatsoever (as opposed to zero bars, but still LTE signal registers) in areas where I had stock signal, but I do often see lesser bars.

While I would be tempted to say it's cosmetic, I will often be travelling in an area (like down an interstate to and from work) where I know there's STRONG, STRONG LTE signal and I will see the signal meter cycle through from FULL bars to zero bars in a minute's time. And then a couple of minutes later it will do it again. And again... I'm still registering an LTE signal, but the CM meter is briefly saying zero bars. (Not "no signal" but allegedly a weak signal.) Yet, I KNOW the LTE signal from AT&T has NOT changed. I'm NOT in some weak LTE signal area. AT&T has specifically stationed LTE towers up and down the entire interstate corridor, especially in the Atlanta metro area. Believe me! Also, this is not during some heavy congestion period, this is also at 4:30am when traveling to work.

Now, I am still using CM12.1 so I don't know about CM13 -- if that bug is still there.

Also, July 2014 CM made some change where when I leave a Wi-Fi connection (like my house or work) and get into my car, the phone first connects to the mobile data at HSPA, not LTE even though there is strong LTE signal. 10-15 minutes later, THEN it suddenly "finds" the strong LTE signal that was there all along! Boom, almost like a clock, it switches to LTE. (On my way to work, I can predict the place where it happens -- since I drive the same speed and same route.) Obviously something in the OS has "timed out" and it finds the LTE signal which was there all the time. I can bypass this "glitch", if when I first get into my car, I PULL OUT THE SIM CARD TRAY for a few seconds, then put it back in. At that point it will reconnect to the mobile network and will connect to LTE. Putting it into Airplane mode/taking out of Airplane mode does not work. Only by actually pulling out the sim card tray -- after leaving the Wi-Fi network -- forces a re-set to whatever code clash CM introduced in July 2014.

When this first happened, I could revert to late June 2014 CM nightlies I had saved and the issue was not there. But as other revisions, improvements were made to CM I had to decide whether this was a deal breaker or not. I decided I could live with it. I would eventually get LTE (after 10-15 minutes) and when driving I'm just using only Waze traffic app anyway and it doesn't need LTE to work. Also, strangely very occasionally this bug does not manifest and I do get LTE IMMEDIATELY. Like 1-50 times, it will be LTE after Wi-Fi, just like it should be. Again, I'm still on CM12.1, which went End of Life in April 2016. I saw some bugs in Marshmallow I wanted worked out first, and now I'm just procrastinating. :p

So, while I've never had no signal whatsoever in CM where I have a signal with stock -- I will agree that there is SOMETHING in CM that does not replicate stock signal reception like it should. It will show weak LTE signal sometimes (possibly cosmetic) where it should be strong or will downgrade to HSPA (not cosmetic) when I can PROVE (through the SIM card trick) that there is strong LTE signal present. There's a bug somewhere in the metering and/or reception code.