Although rooms might not have much theming, the lobbies in many of the DVC resorts are pretty awesome, but not Mickey Mouse. We get transported to a fantastic destination the moment we walk into AKV, OKW, etc. We don't get that at a Marriott, HGVC, etc. (despite being very nice and maybe even "better" furnishings, etc. than DVC). And though nothing is guaranteed, with the new Star Wars, etc., I don't see the resale pricing of DVC going down any time soon. DVC is about the only TS that I'd hold and somewhat "expect" to get most or all of capital outlay back, esp. if purchased resale. Riviera with new restrictions is too early to tell.
As far as % of net worth. it's a luxury purchase. I'd advise to only spend what you can afford to lose from your net worth and not lose any sleep over. Net worth is relative--does it include house, which one needs to live in, and cannot liquidate quickly, does one have a pension, free or very affordable medical care, etc. in which case, one "needs" less net worth in retirement, etc.