the gaggia cubika is a good machine at its price.
because this machine uses commercial filters the grind needs to be spot on.
the supermarket coffee will work better through the breville ikon than the cubika (ikon has dual wall filters, designed for use with supermarket multi use preground (drip filter grind) too course for commercial filters and too fine for plunger.
find best grind just slightly coarser than espresso.
espresso grind will clog the filter basket and can cause it to block or split.
on the cubika i find the drain tray and the steam arm height a pain.
the steam arm lenght is made easier by raising the machine.
the ikon is a thermoblock unit and is probably easier to use