I lived on Grandview Dr. a fairly main street for most of my life and was not bothered by the noise. Occasionally, there would be a loud car with a sub-woofer late at night, but it was generally ok.
There are some very nice homes on Mt. Helix and it is very convenient to downtown via the 94. Growing up there, I will say that many of the surrounding areas are not the best. Casa de Oro for example where one of the closest grocery stores and starbucks is is moderately ghetto. It is not uncommon to notice someone who looks strung out on one thing or another.
However, Rancho San Diego is generally nice and nearby as is the Avocado area. Also, much of La Mesa before you hit University is not bad. The plays in the Mt. Helix amphitheater in the summer are great as well as the hike up the hill.
