So I've made the swap from 165-65 to 175-65 and was very happy. Now I ran across two brand new 185-60s and figured I would try them, I've been still running 165-65 oem size on the rear (I keep finding sets of 4 for $60 since nobody buys them and they sit on Craigslist for months). This combination has been working out fine, I have pretty good traction and handling while getting use out of cheap 165s
This should be an obvious review but the 185-60 has much more crisp handling and the steering wheel seems to hold its place centered much better. The expense is I can feel the road surfaces much much more now, cracks in the road are felt when they were minor before.
The 175-65 handles very well, upgrading from a 165-65 it's a great combination of handling and comfort. Just it can't compete with the 185-60's grip, much more planted and much more difficult to unglue it on dry roadways.
The 185-60s are generally cheaper, for someone looking for more grip/handling on stock wheels they are an excellent choice.
The 175-65s are my favorite however because they offer superior handling compared to oem, not as good as the 185-60 but plenty good for a mpg monster and the comfort they provide is greatly appreciated on rough roads.