New Balance uses Absorb, a soft gel-like pad. Saucony uses the Grid, which looks like the soft part of two tennis rackets put together with air in between. You get the idea. It depends upon which rep you ask. Suffice it to say they are all comparable.
Some runners tend to like one over another, a matter of personal preference.
These are simply standard cushioning materials. So try on several pairs until you find one with the appropriate width for your foot. As for length, make sure you have about a half-inch at the end. It makes sense to try on shoes with the same type of sock you run in. And if possible, try on new shoes after you've done a run or later in the day.