Aluminum cans offer 100% protection from UV and other wavelengths of light that are harmful to beer. There's still great debate surrounding whether cans or bottles are better at keeping beer fresh, but if done correctly, cans are theoretically the superior option. When a crown cap is crimped onto a bottle, the lining of the cap can form an imperfect seal on the bottle, allowing small amounts of oxygen in, as well as small amounts of CO2 out. Over time this can result in oxidation of the beer and lost carbonation. Seamed cans form a much better seal, which can prevent these issues.
Aside from better protection, aluminum cans are undoubtedly the safest option for sharing and enjoying your homebrew. Bring your canned creations tailgating, camping, boating, or crack a few open poolside without the worry of broken glass!
Please note that empty aluminum cans are very delicate, and up to 5% of the cans are likely to be dented or damaged in transit. If the cans were packed in a more protective (more expensive) cardboard box, the cost per can would be more expensive than simply having some dented/sacrificial cans arrive.