It comes down to if you want a new home at a reasonable price in the down town area.
While the location may not be perfect, there are a lot of other attributes, such as close to
a strip mall, whole foods, down town San Jose etc.
If you want to get a feel for KB as well as the area and the quality, visit and talk with home owners at Midtown Plaza at Auzerais and Race/Meridian/Saddle Rack. Midtown has some of the same exact floor plans as Monte Vista. Talk with the neighbors about their experience with repairs, home owners association (Helsing Group), and noise. This complex is 4 years old and should a good indicator of how Monte Vista wil be managed.
That specific area is in a transition phase for the better. It is true that it is near the train and planes but for some that is convenient.
I used to work for a subcontractor that works a lot with KB Home. They have a high level of customer satisfaction and I believe they were rated #1 through JD Powers and Assoc.
Having said that, it'll be really hard to know when things will happen with the area nearby. If it were me, I'd be concerned that there'd be more high density housing built effectively turning that area in a condo village. Resale could be impacted as there would be a lot more competition. Plus the traffic in that confined area would be a concern.
KB Home has a completed complex up the street on Race and Auzerais called Saddle Rack. Most of the area has been already developed and it sits on a main street so traffic flows much better. I staged a condo there recently and the sellers there are motivated. It might be something to consider.
I think the foundational question is "Do you have reliable information on the builder?" Can't say too much myself due to liability issues, but you might check out the following links:
Note, a somewhat common practice this industry is for some of the more serious complaints about quality and reliability to be paid off in trade for signing a non-disclosure agreement. Basically, paying for silence. This is one way you can achieve high customer satisfaction ratings while still having a questionable product, since those that would complain and be vocal, have been silenced.
Research, research, research...