Switchmode design for a general-use benchtop power supply?
If your output voltages are fixed you should be able to design it with linear regulators with a minimum of voltage drop over the regulators. And 1A is not the end of the world.
A switcher would be more appropriate if you have a variable output voltage. A linear regulator which can supply 30V @ 5A, but which is set to 1V out it will have to dissipate 150W.
An SMPS is dimensioned for a certain input voltage, output voltage and current. If you would vary the output voltage its efficiency will be lower. You won't get the 90% figure manufacturers boast about over you full range, maybe more like 75 to 80%.

edit
If you want the +/-15V adjustable I'd go for the SMPS, for the dissipation reason I mentioned. You can attack the ripple with a pi-filter. A high frequency switcher (like 1.5MHz) will allow for a smaller coil.