Good info Rich, I'll have to check it out at some point, so many alternatives!

I've finished adding another stage of regulation to my DIY supply for the RPi and think it has improved slightly from before. The Pre-Tracking reg on the ALWSR board now has an easier time and is fed a cleaner supply, I 'scoped the o/p and there's precious little noise on the 5v line to speak of...not bad for about £25 in parts