I am still digesting the written materials that came with My Primus omnifuel. One thing I notice is that paraffin/kerosene will burn for more than 25% longer than petrol. They seem to say it works best with cannister gas but you 'can' burn other fuels, then lists the disadvantages of all other fuels.
from the manual, albeit abridged.
white gas, coleman type is good, leaves some deposits.
petrol: should only be used in exceptional circumstances due to deposits being left in fuel system and for health reasons.
kerosene, more difficult to prime, more soot and necessitates frequent cleaning. Back in the 50's and 60's many people used these daily and then they caused no problem whatsoever, never seen one taken apart. Is the roarer burner the reason ??
Diesel should only be used when there is nothing else available as is worse than kerosene for soot/preheat/cleaning.
I have to say it is disappointing
as coleman fuel is difficult to obtain locally and if I have to use Gaz I might as well stick to my ten year old £10 camping gaz stove which is many times smaller.