Agreed, big'ish quality thumbs look purty
Something to consider though...depending on how many thumbs you have on a gallery, the page weight can add up quickly. Say you're running 20 pic free sites, so 10 thumbs per gallery...
10 thumbs at 10kb = 100kb page weight
And that's before you add in a paysite banner or any weight for your actual html code, so that page realistically is going to be in the 130kb range. That's getting a bit chubby, as I prefer to keep pages under 100kb total.
If you're running 30 pic free sites, well you get the idea...those numbers add up fast.
It's a balancing act to some degree...finding the best quality at the right size, while keeping an eye on overall page weight. Piece of cake