I'm helping my girlfriend shop for a decent all-rounder road bike for commuting and urban riding, weekend road rides, and likely some light touring. She's gotten into biking on a Panasonic Villager III, a 1980s high-tensile women's bike with steel wheels and Positron components; it's a fine urban bike, but she's getting into long enough rides that it's starting to be limiting.
She's 5'4", more in the legs than the upper body. The shopping list is:
-room for wide tires/fenders
-relatively upright geometry
-preference for classic aesthetics, but at very least inoffensive
-price preferably under $600, so it can be locked up while riding around NYC without undue fear
-light weight and shoulderable, for schlepping in-and-out of apartments
The graphics are simple and the parts seem reasonably proven and serviceable; the wheels seem about as good as one can find on a stock bike and would probably be improved with a tensioning. The cranks seem possibly junky, but would be easy enough to replace if necessary. Any obvious pitfalls on the bike?
Any thing else worth looking at on the market? There's no hard limit on price, but there needs to be good value. To me, the Motobecane CXX looks very well specified but the geometry seems longer and lower, which wouldn't be well suited to someone with a short torso. Most of the other Motobecanes seem flat-out ugly, and also have a racier geometry. The carbon fork many fancier bikes have seems like a bad option for a bike that'll be getting locked up around the city. The Torker Interurban looks like it would be a good bike store option, but costs significantly more for a similar level of componentry.
I know a lot of y'all are enamored, as I am, with used bikes, but we live in Brooklyn, where there are few basements for bikes to sit around in and biking has dramatically increased in popularity with the recently improved infrastructure, so Craigslist isn't really the fount of value it is in other places. Decent-quality 10 speeds are often $200, $300, or more. The Panasonic was a good deal at $150 in this market.
2012 Motobecane Fantom CXX, 2012 Motobecane Fantom CX, 1997 Bianchi Nyala, 200? Burley Rock 'n Roll
I have the Motobecane Fantom CXX and it's a great bike, especially for the price (which is over your limit - maybe you meant the CX). My experience with BD was positive and I wouldn't hesitate to order from them again. I'm not familiar with the Gravity Liberty CX that you linked. It should be serviceable, although I haven't been impressed with Sora brifters (on test rides - haven't owned any), and these are a step lower.
As far as geometry and sizing go, there's no substitute for riding various bikes and seeing what feels good and what doesn't. Typical cross geometry (including the long-ish top tubes) could be fine for someone with a shorter torso. It all depends on what sort of riding position she is after. She could also size down and/or look at a shorter stem (within reason).
^^ Is there a Performance Bike that you can visit? Riding the bike first could be the determining factor for you and your girlfriend. This one offers pretty nice features for the price, including full fenders. It may be a theft magnet, though...