We had a 99 Tradewinds and I thought the National RVs were very well built (the only thing I didn't like was that in ours, all the light switches were on the ceiling - doesn't work well with young kids).
The 03 Islander was built on a 34k GVWR chassis, had a UVW of 29k and had almost 3k of CCC. That's a significantly heavier chassis than our 03 Phaeton (24k UVW/29k GVWR probably about 3k of CCC) or compared to a 03 Discover 39' (28k GVWR / 23k EMPTY (no fuel, no water) - no published CCC but I'm guessing 1k after fuel and water or 03 Revolution 40' (31k GVWR, 26k empty, no published CCC. Also important to note that the Islander has larger tanks (150 fuel, 125 fresh, 70 gray, 70 black) than most comparable mhs (Phaeton is 100/90/70/45, Disc is 90/86/50/50, Revo is 150/95/60/40) so the CCC is actually pretty good.
I actually looked at getting one but because of the CC chassis, they cannot be imported into Canada (to import you need a recall clearance letter from the chassis manufacturer, Country Coach Inc, which is gone. (Country Coach Corporation is a completely different company (with a very similar name) that bought some of the assets of CC Inc and have continued their business but they are not the same company and aren't authorized to provide recall clearance letters)).