All of the schools in the SRVUSD are pretty good. Sure, some score higher than others. I'm a real estate agent living in Twin Creeks and I can tell you that many of the homes I have sold here are to parents who specifically wanted either Bollinger Elementary or Twin Creeks Elementary with the knowledge that their children would then move on to the highly rated Iron Horse Middles School.
Sure, check out the comments on GreatSchools.net. It is a good resource. Even better, give me a call on (925) 997-1585 or email me at firstname.lastname@example.org and I'll put you in touch with some parents of children who go to Twin Creeks, Bollinger or Iron Horse and you get the real facts.
Have a great 4th,