We bought without staying in a
DVC resort, or doing the tour, after several years of research and discussion. We almost did the tour twice, but just ended up being busy with other things on those earlier trips. We knew it made sense based on the way we like to travel, so we were pretty sure we would buy at some point.
We'd started going at least once and sometimes twice a year, always staying in deluxes and usually getting either a suite or two rooms. (DM likes to join us on many of our trips.) We bought DVC last year instead of taking a second trip last fall because we realized just how much sense it made for us.
We bought two contracts - we knew we wanted an Epcot resort, as Epcot is the favorite park of all of us except DS. We have stayed at both BC and BWI before, so we knew we liked both locations. (I prefer BC, but DH and DM prefer BW, so we ended up buying at BWV.) We also bought at AKV because we always stayed Club level prior to buying DVC, and we knew owning was really our only hope of getting it. DS is an animal nut and AK is his favorite park, so we knew AKV was a good choice for him. We'd never actually stayed at it - we either stayed at Epcot or monorail resorts - but we love Jiko, so at least we've seen the resort a bit. We have contemplated adding on at BLT and we will almost certainly add on at Ko'Olina without visiting it first.
We've only had one stay on points so far - using developer points at SSR. We loved the extra space, and felt it more than made up for the loss of daily mousekeeping. We don't regret our decision to buy at all, and aren't sorry that we didn't wait to take a tour or try out the rooms first.