Windows 10 as an upgrade or fresh install?

Hi,

I've been reading several posts here about ways to install Windows 10.

I have a MBP mid-2012 (upgraded to i7 + 8GB ram) purchased in 2014 - and on which I already have both Yosemite and Windows 8.1 (the latter through BootCamp - latest version available in April 2014).

I'm reading here about waiting for BootCamp update for some drivers issues that may arise under Win 10, then others seem to say they are not having issues (or maybe not discovered yet ?) if one is simply ''installing over'' (upgrading rather than clean install). of Win 10. As I rarely need Win 10, all that matters to me is that it works snappy enough (no lags) - no complex applications here, so I would expect an ''install over'' would be ok. (Aside fact I don't want to have to reinstall everything under Windows...) Other experiences about this ? Should i interpret that for the advice being read about waiting for Bootcamp update is only for clean install ?

Also: I just saw the icon under Windows this morning to ''reserve'' my copy of Win 10 so I did it... So when I get the ''next step'' available, can I safely go with it just as when I have Windows updates going on (or when I went from Win 8.0 to Win 8.1) ?

Thanks,

Rob