Each brand has its pros and cons. When looking at a typical Naples home, we use an air-cooled unit. An air-cooled generator is a v-twin, air-cooled engine, a rotor (revolving field), a stator (stationary field), a controller (the brains), and an enclosure. Some manufacturers use an aluminum enclosure, while others use a composite enclosure.
In our experience working with generators, we have found that many brands offer similar equipment in terms of features and longevity, however, we highly recommend either a Cummins or a Generac generator. These two vendors have proven time and again that they have our backs with stellar customer service, and their competitors have not. Some competitor brands were estimating weeks and even months to get a replacement part for the generators, however, Cummins and Generac efficiently had them to us within a day.