While Gridcoin and Burstcoin both do use hardware very differently to most conventional cryptos, the key defining factor is actual benefit to society achieved by the former. Burstcoin functions on a proof of capacity. I can 'mine' it by hooking massive amounts of blank storage together that does nothing and fundamentally achieves nothing.

Gridcoin requires miners to contribute to scientific endeavours through the BOINC platform. While mining, you may discover a new stellar phenomenon, or a new megaprime, or an unknown cancer marker. I honestly consider that on a per user basis, GRC does more good for society than any other crypto.

However, that is coming from a researcher, so I may be a little biased. =)