Good baguettes are more difficult to find in America than good croissants, although shitty baguettes are frustratingly abundant. Like croissants, baguettes should be light and airy on both the inside and outside, with a crispy shell and soft interior. A good baguette outer shell should be legitimately hard; if you press you fingers against it, it should feel like a real shell with little to no give. The inside should be fluffy and light as cotton candy, with plenty of air holes; if it's dense like a German loaf or squishy like American sliced bread then it's all wrong. The keys to a good baguette are air inserted into it during baking to maintain the proper lightness, and a total lack of preservatives, fats, or oils, which ruin the consistency. A proper baguette should go stale in one day.
American bakeries, even fancy artisan ones, virtually always insist on adding some kind of preservative (or fat or oil to act as such), which is why you can almost never find a decent baguette in America. Personally, I grade American baguettes on an A-B-C scale. Grade C baguettes are basically just American bread that's vaguelly baguette-shaped, and are common at general grocery stores like King Soopers. Grade B baguettes may have a properly hard shell but are too dense in the interior, and are common at independent bakeries or stores like Whole Foods. Grade A baguettes are actually French-like and are very rare, although the really good artisan bakeries and French-American bakeries will often produce what you might call Grade A- baguettes that are almost right, except they have too many preservatives.
Paul makes a Grade A- baguette. I have only had legit Grade A+ baguettes at one place in America, at an expensive French restaurant with an in-house bakery.
Left side: Bad!
Right side: Good!
Montreal Gazette