Jaque's definately prefer higher humidity - not overly high, but at least 60%. Mine suffered when humidity was under 50%...and has since bounced back. It was growing fine when humiidities were in the 60's.
Phis, I misunderstood you - you're right - they won't die without showing signs. All of mine started to shrink before they croaked.
eymae is a great plant! It's very closely related to maxima - and the lowers look very similar. However, they're not that much easier than jaques, in my experience. Maybe a little less sensetive to environmental flux. It DOES grow faster.