The Voice comes off as having more talent than Britain's Got Talent or the X Factor because whoever is responsible for sorting applicants has already weeded out the people that, sadly, don't make the grade. Therefore the show doesn't 'waste time' during the auditions on people that are real no-hopers because they're good for the ratings. Likewise, The Voice doesn't have people like Wagner who are rubbish singers but good entertainment (and therefore good for ratings) so the end result is The Voice has more talented singers on it.
This is one of the main reasons I like it, it has less dross and less of a bullying undercurrent.
I think Jessie J and Will.I.am are honest. Not sure about Tom Jones or "The One from the Script".