Remember to book the refuge before you leave: http://www.vosges-trotters-colmar.fr/le-...
The refuge is comfortable (drinking water, electricity, toilets – but no showers – kitchen equipped with wood stove, crockery, fridge, games), and you sleep in dormitories (blankets and bolsters are provided, but bring a sleeping bag or sleeping bag liner). Drinks can be purchased on site. Some rubbish can be left behind, but recyclables must be taken away with you. The welcome is warm and the setting is beautiful.
For the sections on the GR®531 (Rectangle Bleu), be careful, especially in wet weather (metal steps, handrails and ropes, scree slopes), as some areas are tricky, although very beautiful. Nevertheless, we managed it with our full backpacks (we set off for two days with sleeping bags, clothes and food for one adult and one child per bag) and the children loved it (aged 7 and 10).
You can buy farm produce or eat at the various farm inns along the route (Hohneck, Kastelbergwasen, Schiessroth, Frankenthal, at least the ones we saw open when we passed through).