It's more on the old/pretentious side. Not as bad as some.
Winston is slightly tarnished by an association with the book 1984 and a cigarette brand. It's not sweet. But seems a bit less awkward than most -ton names, thanks to W. Churchill.
Mostly it seems trendily just another surnamey, placey -ton surname. Not really pretentious -
Windsor would be pretentious - but maybe pretending to be pretentious.
Preston,
Easton,
Weston,
Kingston,
Payton,
Colton,
Braxton,
Ashton,
Leighton ... so of *course*
Winston too. Whether it's used a lot or a little, it still gives the trendy impression to me.
Overall I think it's fine, but I don't like it.
- mirfak