I just bought but I can give you some insight into what I have already learned.
If you think you will usually be booking within the 7 month window, then I agree with the above suggestion to buy SSR or an extended OKW contract. That way you can also buy more points for your money. At 7 months, the availability is often the more expensive stays. Which leads me to the need to buy a few more points than you think you will need, especially if you think you will be traveling over spring break, thanksgiving or Christmas once your kids are in school. If you go during the off season, this isn’t as important.
From a value perspective, I would say that you know your travel style best. If you would always book value resorts after hunting the best price, then your DVC vacations will cost you more than you would otherwise spend. My back of the envelope math put the cost of a studio stay at AKL at roughly $300 a night over the course of the contract, including maintenance fees. The cost of the one bedroom was around $530 a night (and these would be shorter trips). This is a good value, when you consider inflation, if you will continue to go to Disney, and you stay Deluxe.
I will note, as much as my heart belongs to the Boardwalk, I could not buy there because of the shortened contract time. In comparison to AKL the shortened contract makes the “cost” of a studio there roughly $480 and a one bedroom $663. Even if we eventually decide to sell, I would rather be selling a contract with more time on it.