Aadamsmom - we live in Ruislip too! The commute to Reddiford is easy and quick, much better than Orley Farm would be. If you dislike driving then you will find the commute to Orley a pain in the butt! Now, I have my DDs to drop off at school in Northwood, so I do a fair bit of running around, but if I only had DS to drop off at Reddiford - piece of cake. If you hate driving then the H13 bus goes from Ruislip to Pinner, and would drop you off really close to the school if any day you didn't fancy driving. You would probably be able to figure out car share with someone once school got started, the school is small enough to get to know people, plus school or PTA would be able to get word around by e-mail too. I know that some people to have arrangements in place. Not sure how many other Ruislip people are around in the school. In DS's year not too many if any....
You say your DS is quiet and shy, so is mine. I think that Reddiford is good for a child with those characteristics. Not only are the academics good, sport is fine - swimming once a week all year round, PE seems quite varied (they have a number of sports teams for the older year groups and do matches etc). As I said before there is none of this "rugby culture" which you can find in some boys' schools, you know where rugby rules supreme and if you hate it you're sad/a dork/insert any other insult. The pastoral side is good, and in DS's class they've had a lot of discussions about being a good friend, including someone who doesn't have anyone to play with etc. There are clubs, extra-curricular activities, all the typical things.
I think a lot of people overlook the school as the buildings are rather underwhelming and because they go off-site for swimming and in the older years for some PE. But for me, when we visited, the children all looked genuinely happy and enthusiastic, they were confident in a nice way. It is a school that will build confidence, as I can see it in my DS who is quite a 'late bloomer'.
Where else are you trying your DS apart from Orley? Any of the Northwood boys' schools?