Along with Machinehead above, I've owned both of these basses and still have the US '75 RI which I bought on the strength of the Squier; my reasoning being if a £250 Indonesian built bass plays and sounds as well as it does (and it does, believe me!) how much better will a £1000 US built bass be? The answer is 'A lot'. The Fender is without a doubt the best bass I've ever played and I have to agree with Machinehead regarding the materials used, the build quality, electrics & pickups etc.
Don't get me wrong, the Squier is a fabulous bass and I recommend buying it but if you can find a 2nd hand US RI you should opt for that instead. Trust me, you won't regret it!