Im not sure what your major concerns are as far why you are buying and what is most important to you. I would really suggest Danville over San Ramon windermere. Maybe im biased because i lived in danville and still maintain a home there as a rental. That being said, I think Windermere is a beautifully planned community, and i think they are doing a great job with the development of the community. The major downfalls i see besides the prestige of the name compared to san ramon is the huge amount of houses that have been built in the area. The huge development has lead to alot of inventory, and prices in the windermere area, have slid due to investors and buyers bailing out of there new construction purchase after a year or two. With the New builders unloading houses at discounts and the listings of Newer homes that are for sale competing with each other. This i see as a issue, and who knows if the builder will lower more in order to deplete there inventory. Those that bought high are taking losses and there are short sales in the area for comparible homes as the New construction.
The Pros for San Ramon, the easier proximity to the freeways than the danville location if it is the development off tassajara across from blackhawk. The New High School and schools is a positive, but danville also has some the best schools in the area. San Ramon is alot closer to major attractions, besides Blackhawk plaza danville is pretty secluded in that area.
Now for Danville. Tax rate is better, lot size advantage, and overal location of the development is secluded and across from the country club you might as well call it blackhawk. Very nice area. With a smaller developed community danville has more older homes, and not much competition between new homes just built and your new construction. So there are not people unloading a house that was just built ayear ago. To me its a choice of older town feel established community compared to a more new develpng community that hasnt showed its character yet, and yet has proven itself to hold its value.
My other concern is KB vs Centex. This is probably the biggest variable i have not heard much about centex homes, yet have heard some stories about KB. Do you research on the builders. Did you not like the Alamo Creek homes by Shappel. I was close to buying one myself, but chose to move to SIlvercreek due to commute reasons. But i loved the floorplans and the options in those homes, and i have heard always great things from shappel. I know they are a but more, but it might be worth looking at. This is where a realtor comes in handy, and builders in the area welcome realtors to help you make the right decision.
Lastly on a comparison for last mnths last closings, San Ramon held its value a bit better overall. San Ramon with closings 145 avg price $813,000 one month ago $800,000 + 1.63%. Compared to DANVILLE closings 112 avg price $942,000 one month ago $1,000,000 -5.80%. These are just numbers that can be due to many variables, your best bet have a proffesional help you and do your research.
Also did you look at Newly listed properties on the MLS, that are new homes and comparible. San Ramon has some other beautiful areas besides windermere that might compare better to danville but it might not be a new construction.
Hope this helps and good luck.