Change in service quality.

I live in a mountainous area in northern California.
Five years ago I switched to Verizon from ATt&T
because the CDMA prodocol worked so much better
in this area. I was also instrumental in many of my
friends and associates (we're  talking more than 100)
signing onto or even switching to Verizon because of
the better connectivity and over all service, and
because of the no-minute-charge mobile-to-mobile service.

Recently, within the last three to five months,
Verizon service has changed noticeably even dramatically.
So much so that some of my friends have changed providers.

Symptoms of the change are:
1. wider dead zones
2. Often smaller bar connection in previous "hot" areas.
3. "hanging calls"  i.e. you dial land the phone sits on timer.
You have to hang up and call again, sometimes several times.

While these may be common cell phone user experiences and complaints
they are new to us in this region. And more im****tantly it represents
a change.

Some Verizon users re****t a return to better service and diminishment
of these symptoms when they purchased higher end Verizon phones.

Sprint and US Celluar users re****t NOT having these problems.

So, far Verizon has been unable to provide a remedy or even an
acceptable explanation.

I'm posting here to inquire if this is a change experience beyond our
regions.
And, of course, if anyone can offer an explanation or solution.

Thank you
CR