As I posted earlier (somewhere on the forum), I'm about 5' 10 1/2" with an inseam of 30.5" using the book on wall measuring bit and shoes on. Every bike chart I see says I need about an 18" frame, but when I straddle I snuggle, so to speak. Lady nearby has a nice circa 2007 Diamondback Wildwood small (16") for a good price, but I'm leery of getting something too small. I've had a road bike that was nice but too big and don't want to go that route, again, even the other way. Tried a couple of nearby LBS but, even there, I come away scratching me head. Also the local REI but the "bike guy" acted like he would sell me a small frame because he had one available.
So, would I be sacrificing a lot with a 16" frame? I'm just going to ride in the neighborhood but we do have some fairly long hills.