I'm sure you will ALWAYS find people with regrets... my feeling is usually they regret it because the over extended and can't afford the dues, payments, etc. Or they get upset at a policy change.
Overall, I think most people are satisfied. It makes getting the room you want much easier, there are some nice perks (the AP perk is my favorite, but remember a perk can go away at any time so don't buy based on that... after all, some resorts used to have free valet parking) and you've lock in the price of the rooms. If and when prices for rooms rise, you will save significantly. Plus you don't need to come up with that money for your vacation.
But, in my opinion, if you aren't planning on going to Disneyworld,
Disneyland, Hawaii, Vero, or hilton head, trade your points for another week somewhere else or rent your points every 2 years, then
DVC may not be the best fit. We go down once a year, so the number of points we have works for us right now. We can always rent them if we won't use them or use them elsewhere. But if we didn't go on vacation and didn't take the time to rent them and just lost them, it would be a waste.