I live down the road from Mission Terrace, and currently have clients looking at homes there. Bottom line: It's a good area if you need freeway and Muni access. Could be better in terms of restaurants and other services. But you're close to Bernal, Noe, Glen Park and Mission establishments. Mission Terrace has a solid neighborhood feel and houses are typically priced in the $600,000s and up.
As you'd want to do with all neighborhoods during your home search, check out Mission Terrace at night and at various times of day.