I've got both and I thought the mkii was great at first. BUT. My cup now emits a horrid smell (probably the anodizing burning off). I love how lightweight it is, but I'm not convinced that it would stand up to much abuse – no way I'd put it into a fire to cook. That said, it's still working, and I try to be careful with my kit. I have been playing with ditching the MKII one for my steel crusader – they don't fit as well when cooking, but I'm not really worried about absolute thermal efficiency with firedragon blocks/trangia (that's what my jetboil is for). The Mki cup is a special bit of kit – they really got it right designing this. Only drawback is that it's heavy (but I'm also carrying an axe so for me that's a ridiculous point.