In the September 2014 edition, Elektor have published a 'Professional Lab Power Supply' project. It takes a dirty 12 volt input, typically from a ATX desktop PS, inverts, transforms and rectifiers it to a voltage about 2 volts above what it wants, then sends it through a linear regulator. So it has electrical isolation between the input and output and claims up to 70% efficiency.
Is there anything uSupply could learn from this Elektor project? For example it gets around op amp voltage rail problems by using several DC/DC converters to obtain +- 15 volts.
For those that can't see the schematic, it uses an Atmega32 for control, and opto-couplers for feedback. The output voltage is 0 to 30 volts, adjustable in 10 mV steps while the output current is 0 to 1 amp, adjustable in 10 mA steps. IMO more current (say up to 2 amps) at lower voltages would be useful.