I partially disagree with the previous posters, and since I used to live in Vista (as well as San Marcos, Temecula, Carlsbad and Encinitas), here is my advice:
-Look at San Marcos. San Marcos is a million times nicer than Vista and there are areas where the prices are comparable. The city of San Marcos has budget surpluses; Vista is dirt poor. Walk into the city building in San Marcos, look around at all the new and planned development and you will be impressed. Not only is there already alot of nice shopping and new communities, but they are planning, get this, a $1 Billion development of the creek area in San Marcos in the next 15-20 years! Discovery Hills homes begin in the low 500s and it is right near this new development area, and the university that has 12,000 students but will grow to 20,000+. Current developments going on within 5 miles of Discovery Hills: An amphitheater at San Elijo (Twin Oaks will open up and you can drive through to Encinitas in 1 year too), an outdoor theater/LA Fitness near the city building, a Nordstroms Rack and others.
-If you must look at Vista, stay south of the 78 and look at Shadowridge. Melrose Dr. is now open at Palomar Airport Rd and you can take that right into Shadowride and avoid the 78. The Vista neighborhoods there are just as conveinant to the 5 as Carlsbad’s Rancho Carillo and Bressi Ranch and 1500 single family homes sell for the low 500s. I lived in that area and it is the best area of Vista. I would never move back though – Vista is not a well run city, they have no money, schools are sub-par and most of the city (Shadowridge and a few other areas excluded)looks like Tijuana.