I lived across the road from the tracks a little further down- and I heard them ALL NIGHT LONG. Passenger trains were barely noticeable. There was one freight in particular that used to come through at just before 2am. If you're a light sleeper I wouldn't recommend.
I am in 15 Kurrawa Avenue and I can tell you the freight trains run several times a day and night and the noise is horrendous. The traffic is only increasing. Wearing ear plugs helps a little. There has been complaints to Parliament as the noise reachesd 90 decibels but nothing has been done.
There is some noise depending on where exactly you live in the area but in my opinion nothing compared to living anywhere within 10 km radius of Sydney airport for aircraft noise or along any railway line suburbs in Sydney. One of the many upsides to Point Clare is a great waterside suburb with a number of nearby railway stations and close to the M1. Imagine a house on a quarter acre block in a harbor side suburb with a railway station such as Kirribilli what would you expect to pay? Depending where you buy at At Point Clare you could find a really nice home from about $600-700K with potentially great views over Brisbane Water.