In the right hands it can work quite well.
Because the wire is so flexible you can't feed it thru the main cable like normal MIG wire and therefore need a spool-gun attachment. And of course the shielding gas is different as well.
not to say the opposite of what you posted , but with a decent wirefeed , you can just replace the steel wire , and just need to switch the type of gas used .....
BUT you need to do the following .......
if the liner is fairly new , you can remove it and wash it out with laquer thinner .
teflon liners are also available .
if the liner is broken , really dirty or old , just replace it with a teflon one
then you need to set the tension on the feed rollers so it slips on the wire rather than bunching up into the rollers when the wire is held motionless at the tip .
you need a new tip in the correct size for the wire used
the wire feed needs to be a 220volt model ... a 110 isn't heavy enough to do a decent weld .
alumimun requires alot of power to be welded properly .
you need to keep the wirefeed cable from the welder as straight as possible , and shield the nozzle from and moving air that would blow the gas away from the weld .
while your welding you also need to set up how it welds to what is called a " spray transfer " .
gas presure plays a vital role too ..... too much gas can cool the weld too quickly , not enough gas can cause a porous weld .
and most of all ....
practice practice practice ..... and cut some welds apart to measure how you are doing .
BUT if you had to weld the stuff everyday ... go buy a spool gun and and avoid the pain in the ass of having to have everything "perfect " .