Both of these communities have diferent things to offer. They are both fairly new but otherwise there are some differences:
The Crossings have single family homes, townhomes, and condos as part of the development. The single family homes have 3 or 4 bedrooms and small back yards. the townhomes are 2 and 3 levels either 2 or 3 bedrooms, and no yards. The condos are from 1-3 bedrooms and there are elevators, and a few balconies. The communities have pools and parks. The schools for this community are Los Altos with I think almond elementary, (it used to be Santa Rita but I believe the boundary changes), Egan Middle School, and Los Altos High.
Whisman Station is a little newer and has single family homes and townhomes. The single family homes are 2 story with small back yards. The townhomes are 3 stories with very small front yards in the older models, but some of the newer ones do not have any personal grass. The community has parks and pools. The schools for Whisman are Mountain View, Landels Elementary and Mountain View High. The community has been cleaned up.
If you are only keeping it for 5 years and like Whisman better then I would choose that one. If you were planning on staying more than 5 years I would go with the Crossings. The reaon is that as the communities age the location will have more of an influence on re-sale. since the schools are more desireable and the ammenities closer The Crossings will be more popular. There is one caveat to that and that is if you are speaking specifically of the condos at the Crossings, as opposed to the townhomes or single family homes, then a townhome in Whisman Station will hold up better than a condo at the Crossings as townhomes are much more poular than condos. If you need some more info on the difference between a condo and a townhome you can go to my website http://www.marcymoyer.com
and click on the link the difference between a Condo and a townhome.
So I hope that helps.