I am not all that familiar with La Mesa, so I can just give you an outside opinion from the anecdotal data points I have gathered.
Everyone I’ve met who lives in La Mesa loves it (maybe 10 ppl I know).
I’ve never heard anyone who doesn’t live there diss it at all.
North of 8 seems to be typical tract homes, some very nice.
South of 8 seems hilly with larger single stories with nice views, more custom built. I’ve been to a few house parties south of 8 and there are some amazing views, I tell ya.