I have the Crusader mug and it's good kit. I'd never leave home without it for either civ or mil stuff (what else are you going to drink out of) - get the plain metal version and not the non-stick one though as the non-stick coating soon flakes off after being bashed around a bit. I love it because it fits inside the 58 bottle, but I don't see the point of getting a lid or a hanger for it, from what I can see they aren't going to fit inside an issue waterbottle pouch very handily and you can't stow the mug with lid attached if it's wrapped around the bottom half of a 58 bottle now can you? Don't worry about a separate plastic mug or burning your chops, just get some tape on the brim and perhaps the handle to avoid that.
I was just going with the Crusader and hexi (often augmented with a Jetboil for easy fast cooking, Crusader was then for drinking only and hexi was a back-up fuel source in case of running out of gas) as I was used to eating boil-in-the-bag rations, MoD supplied. After a trip to the north of Iceland where, (although we weren't out hiking per se for 2 weeks we certainly lived remotely and rurally for that time), our group caught and cooked fish to augment our diet, I realised that any overly-specialised cooking system is not a panacea. I then remembered how in Ecuador we had done the same. Can't really sort out cod or berries in a pint mug or a jetboil very practically can you? Can't really put a jetboil over an open fire to save your gas either.
Now I still take the mug and jetboil/other stove set up (they are great for when you have got ready-to-go, easy-to-prep food like ORP or similar), but also made sure to pack an old West German mess kit (pail and skillet style, like the German ones in WWII war films but from the 1960s instead) in a sidepocket of my bergen. Takes up no room in real terms as you just fill it with other stuff you were going to carry anyway, and it was cheap as chips brand new, no stove needed to be bought either. And while it's not that likely to get used day-in-day-out like the mug and jetboil will be, whenever we get a bit of locally-sourced kill-catch-or-pick-it-yourself scoff next time it's going to come in a lot handier than all that 'hi-speed lo-drag' stuff!
I'm actually in the market for a billycan now too, as an equivalent to the pail & skillet for my civvy kit (trying to keep mil and civ kit separate as much as possible so's I don't look like a squaddie doing civvy stuff and so my kit is ready to go with no fuss for mil stuff) - where's the best place to get a 'Zebra', does the little dish inset come in handy, and are they recommended?