hexohm has lifetime warranty but g class has a lot more features. If you don't care about temp control and fancy screens just go with the hexohm V3. it'll last you as long as they stay in business and I don't see them going anywhere anytime soon
Love my Hexohm V3! But I don't own a G class so I'm a little biased. I will definitely agree that a hexohm will last you forever internally. The paint comes off the hexohm symbol kinda easy though as a warning.