Another vote for Moom here. By default it doesn't have any Aero Snap style drag zones and only presents itself as a hover-popover attached to the green button,

Another vote for Moom here. By default it doesn't have any Aero Snap style drag zones and only presents itself as a hover-popover attached to the green button, which is perfect for my use of snapping which is only occasional. Its ability to divide your screen into a grid of your choosing is nice too. Yes it's not free, but it's a cheap one-time purchase and I've been using the same license for a decade now, so it's close enough to free that the difference is moot.