Aluminium vs Plastic:
ALUMINIUM IS FIREPROOF while plastic gutter protection products are only treated with flame retardant chemicals. Although plastic might not burn, or catch fire, plastic will melt if it comes into contact with embers.

Unlike plastic, aluminium will provide repeated protection from the risks of windblown embers during bushfires.

As it has a melting point of over 650˚C Aluminium will protect your gutters year after year, season after season.

Aluminium will not sag, warp or discolour due to the expansion and contraction caused by summer and winter temperatures or the effects of UV. This is one of the reasons why it is used in the construction of aircraft.

Aluminium will not become brittle after a few years allowing birds and possums, or rats, to pull it loose or chew through it to gain access to the inside of your roof.

Aluminium vs Steel:
ALUMINIUM Aluminium develops a natural protective coating by surface oxidising when exposed to the atmosphere. This protects the aluminium from the effects of corrosion (rust) and in doing so eliminates the requirement to add additional coatings.

Roof sheeting and gutters are primarily constructed from Zincalume materials and this protective coating consists of a blend of zinc and aluminium so there is no risk of the aluminium causing a galvanic reaction with the roof sheet or gutter.

Aluminium is also lighter than steel and this means that once installed it places less weight on your gutters. 

For DIY applications aluminium is far easier to work with as it is not only light in weight and very strong once installed, it is also easy to manipulate when forming around overlaps or defects in any roofing material ensuring a perfect fit and eliminating the need to fill all the gaps with silicon or other sealants.