How much vacation time do you get a year?
Also, did you use HGVC thru RCI for these destinations: St George UT, Grand Canyon, Brice National Park, Zion National Park, Kolab Canyon, Valley of Fire State Park, Snow Canyon State Park? These are the places I would like to visit using a timeshare but HGVC does not have anything close (except for Park City I guess)..
So far all my stays this year have been either Wyndham or WorldMark, My two Orlando stays 1 is Sheraton Vistina over Christmas week. Exchange with Wyndham points in RCI. The other is a Platinum Escape week from Interval.
I get 5 weeks of vacation, benefit of working 20 years same company. I generally take 2-3 week long trips, the the rest I either do as 4 or 5 day trips. Doing it this way allows me to do a lot of trips a year. Sometimes it seems kind of wasteful one of Platinum Exchanges is for a week but I'll only stay 2 Nights and 3 days.. But got it for $97 bucks so I will go have fun. My Christmas Exchange is a week, but again I won't use all week, but will probably give remaining days to kids to use.
If wanting to visit parks I have listed above Flagstaff, AZ (Wyndham) area would be good for Grand Canyon, The rest St. George Utah (WorldMark) is a great base area to see stuff from except Valley of Fire, This about 30 minutes out of Vegas.
If you want to see Arches, or Canyon Lands your best bet is get a hotel room in Moab.
I am a WorldMark fan... You can take 1 day to a month long trip and even do group reservations over many resorts allowing for cool road trips if you have the time. Last minute exchanges to RCI or II are just 4000 credits. About $280 MF for most people, ones booked longer in advance are more 6,000 - 10,000. But you pull almost all inventory with them in exchanges. This gives you access to, Marriotts, Hilton, Hyatt, DVC, Sheraton and many others. You won't get prime holidays, but I can always seem to get something I want out side prime holidays. You can get prime holidays pretty easy in Orlando and Vegas if you put search in early.