What actually I wrote in my second post was this:
"I admit I've never tried to phone anyone from Silbury, however, in many of the locations around Avebury my mobile doesn't receive a signal ... which is just fine by me.
Thanks for the info, have also read the other posts on this subject - looks like an interesting development."

Perfectly polite, admitting I might be wrong about the phone signal.

Alan, well done for researching these, which are going to be a big thing that we'll all benefit from I reckon, so it would be a shame if any negativity was dumped on them, especially with zero justification. So let's make it clear - no-one ever suggested they will replace normal text so there's no reason to point the fact out, as if it's a problem to be overcome - it's a bit like saying beware buying a radio, it won't replace books! Also, there are 30K Scheduled monuments so alleged phone problems at one of them is hardly an issue - especially as the info can be captured and used later.

There's so much bad going on in heritage at present, with the funding cuts, this is a 100% Good News story that's going to be great. EH and NT et al need nagging and encouraging to embrace it. Arguably, this very website will play a massive part in it.