I lived in Kensington growing up (1986-1998) but didn’t get over to Talmadge very much. However, I considered it a nice area. However, it seems to lack the “main street” walkability of Kensington.
I have known two couples who lived there. One couple (two editors) lived there from roughly 2000-2005 and moved to Carmel Valley when they started having kids.
Another couple I knew (two physicians) bought a home and lived there from 2005-2008. They liked it a lot and had one child while living there, although he did not start school there. I think they lost money, though, given the situation in the real estate market when they had to sell in late 2008.
I’m not sure what you meant by “the gated area”. Are you talking about Alvarado Estates? Or is there another gated area in Talmadge itself? See, I am really not that familiar despite living within a couple of miles from there during my formative years.
As for schools, you may be able to choice into Hearst/Lewis/Patrick Henry in Del Cerro/Allied Gardens. Those schools are still fairly decent, from what I understand.