As a new member here, although long time member on the Shad's sites, it's probably best to remeber that the Shadows became very family acceptable quite early in their careers, having started out as rock and roll.
But from my side of the Atlantic the Ventures were a Surf band along with The Surfaris, Beach Boys etc, it was only much later all instrumental bands got lumped together as a genre.
I was at school in the early 60's when all of this started and many considered The Ventures as much cooler than The Shadows.
As for me, I find quite a lot of Ventures recordings we get over here as not great, a lot seems just fast for the sake of being fast and the tune gets a bit lost, having said that a lot of people regard The Shadows later offerings as "lift music" nice enough but just instrumental covers of famous vocal numbers.
But I think all of the 60's instrumental bands in the USA and Europe had good and bad, probably all down to the record companies demanding another record when the bands had nothing much to offer, you can't just whistle up brilliance on demand.
So to try and say one band was better is a bit like trying to compare say Dylan with Cohen, Vai to Satriani, or even Sinatra to Davis all have similarities but have their own identity.
But for me long live guitar music, coz whilst the fingers still move OK the voice is getting - lets just say err weaker??