I love it in Montclair, and if you're looking for a place to live that gives a kiss of the beach.
I telecommute a lot, and finding a quiet place that isn't an absolute drag is key. A lot of my younger days were spent wishing that I could get to Myrtle Beach on the east coast with a lot less trouble, and if you're an East Coast kid like me with the same problems, Montclair is what you're looking for.
Under 40 miles away you can reach a few beaches. Perris Beach, Moreno beach, Surfside Beach, North Star Beach, and Alamitos Bay beach are all just over 30 miles, and the farthest beach that can be considered "in the area" is Newport Beach about 36 miles away.
The best areas in Montclair have to be Rancho Santa Ana Botanic Garden and the Russian Village District. Beautiful places with stunning scenery and a story, so don't leave Montclair without taking a look!
The only negative I can think of is Code Enforcement. The police have important jobs to do and I'm not at all saying that code enforcement isn't necessary. I am saying, however, that getting a ticket for no front license plate after reporting the license plate stolen--all in the same day--is ridiculous.
Aside from administrative issues, it's a lovely place to live with great beach access and a caring community.