Mercer Island is a suburb of Seattle, located on an island in Lake Washington. The best thing about Mercer Island is its strategically central location relative to the greater Seattle area. Connected to both Seattle and Bellevue by the I-90 bridges enables one to get almost anywhere quickly (notwithstanding the ever increasing traffic jams). We have lived on Mercer Island for approximately 11 years and our children have attended the public grade schools here.
Housing on the island has always been very costly relative to the rather shoddy quality of many of the houses. The island was built up in the sixties with rather basic stick-built ramblers. Not of great quality to begin with, these houses have not aged well, and yet comprise the majority of available homes, with prices currently ranging from around $700K to $900K. If you want something a little nicer expect to pay upward of a million. Increasingly developers are buying the old ramblers as they come on the market, tearing them down, and putting up McMansions - those ugly monstrosities that take up the entire building lot, with massive faux-everything facades that attempt to hide their shoddy construction. These are typically priced between 1 and 2 million. The waterfront and anything with a view is extravagantly costly.
The island itself is about 5 miles long by about 1 1/2 miles wide, and is rather pretty, with many leafy deciduous trees interspersed with conifers. There is a lovely waterfront park at the north end (Luther Burbank Park) and a couple of small beach parks further south. There are also a couple of parks in the center of the island that are mostly just forest land. There are commercial developments at the north and south ends with grocery and drugstores and other basic amenities.
Mercer Island once had the reputation of having the best public schools in Washington state, and that drew many families with school aged children. That is still the principal draw to the island even though other school districts have surpassed the Island in recent years. Mercer Island is still probably a good pick for families with young children. It becomes problematic for teenagers because the Island doesn't have anything for this age group to do. Teenagers generally have to leave the island in order to find work and hangouts that appeal to this age. The majority of island families are professional households where both parents are working - there is a superabundance of doctors, lawyers and CEOs here - and that means a lot of high schoolers are going home to empty houses (and the trouble that sometimes implies). The high school, unfortunately, is reputed to be one of the worst in the state for drug and alcohol problems. Kids who are well grounded, though, and have a lot of parental oversight, will be able to do alright here. We solved the problem by moving close to the high school so that our house could be the after-school hangout where there was always a parent present. The quality of the schools, while not great, is decent. A few programs, such as the music program at the high school, are excellent for a public school..
My feeling about Mercer Island has always been that, as Gertrude Stein once said about Oakland, CA, "there is no there there." It's an affluent suburb with a lot of busy, over-scheduled people, and not a lot of character. Still, as in most any place, it's possible to find small enclaves of people with shared interests, and that's especially true for families with young children, who manage to connect through their children's activities.