I've had mine for a few years and love it. Its PVC which isn't as durable as Hypalon but they have extra layering where it counts. The floor is a bit thicker than needed and there doesn't seem to be as much room as a comparable Hyside. The boat can be inflated to higher pressures than most rafts and is really stiff and responsive. Vanguard's been very good with minor warranty issues I had earlier on.
The boat's a very good value if they're still selling in the low $2K range. I'd recommend a 14' boat if you're in Colorado - small enough for headwaters rivers and big enough for the Grand Canyon.
Good luck choosing!
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse