I think maybe it's best to just stay away from anything made out of polycarbonate. It's not very chemical-resistant (that's why they crack/melt) and has BPAs that leach onto your liquid. It can happen in seconds to days, depending on the chemicals in the liquid.
Some companies are using better plastics now (like polyethylene/polypropylene polymers), but from what I hear, people are still having problems with florals, like honeysuckle and cherry blossom. Of the plastics out there, I'm thinking that the safest one I've seen so far is the one they use on CE3s, which looks like the same plastic they use on medical-grade syringes (polyethylene - chemical resistant and food friendly). But if you can find a Pyrex one that you like, that might be best. I would love a rebuildable clearo-type one, where you don't have to insert a poly-fill carto and just replace the heating element when it goes bad.