Sorry, I hadn't seen this post before.
I don't know anything about Glenbrook Valley, so I can't make a comparison. But I live in 77092, in Oak Forest. Forest West, I believe, is just a mile or so NW of me. Although I don't know anything specifically about Forest West, this is what I know about the general area: there are plenty of ugly retail properties, as well as undesireable apartment complexes, but I can't tell you how that affects the neighborhood itself. I can say that it doesn't really seem to affect my neighborhood much. I enjoy living in this area, and I feel pretty safe most of the time. As a female, I wouldn't go walking around in the dark by myself, though.
Don't know if you have kids, but the schools zoned to the area aren't the greatest either.
Traffic--290 is bad, but you can avoid it by using streets to get to 610 instead. Getting downtown is a breeze--just take streets to get to Washington or Shepherd, and you can take Allen Parkway or Memorial into downtown. Overall, that's a big reason I love this area, is because it's really convenient to get to just about anywhere in town.
I would use HAR.com to look up the property value history, school info, etc. to get a good idea of whether it's a good investment or not. Also visit
http://www.houstonarchitecture.info/haif/index.php?. There are a lot of knowledgeable people there that can probably tell you more about Forest West specifically.