Well, down in our part of the World, in the Summer months, we get D-XXXX, F-XXXX, OO-XXX, PH-XXX and increasingly M-XXXX and 2-XXXX as well as the usual smattering of N and G, so yes, the 'G' does matter.
However, I'm with you re use of company callsigns rather than reg.
TOO