You can fulltime in many different rigs and depends on your traveling style. If I was going to be boondocking mostly, would get a rig with more tank capacity and overall larger cargo capacity for increased battery and solar equipment weight and heavier frame. This would make a solitude much better choice than a reflection. But if you are like us, staying mostly in campgrounds and occasionally doing some dry camping then the Reflection line is adequate. The 337rls would give us the option of more capacity and still have the mid profile we prefer to the higher profile solitude for our way of traveling.
We are on our second year of fulltiming with our Reflection 303rls. It has held up well through some rough roads, weather and other than minor issues, the suspension is its achilles heal. I plan to get that reinforced next summer before we head west. I added 2nd AC, disc brakes and a second battery. We carry a portable solar suitcase for dry camping.
Storage is more than adequate for us. But with the limited carrying capacity, I have to monitor weight and we have had it weighed per wheel, and at truck stops yearly. With 20 gallons of water we have onboard so we can overnight along routes, are 150lbs below GVWR of the 303 which is 11,995.