They are... somewhat different. How they frame the rapture, and whom might make the grade on such a junket - I wouldn't say they're fundamentally divergent on those topics because in LDS doctrine exaltation is obtainable by a potentially uncapped number of true believers that strive towards it, whereas for a witness there's a hard cap number on the souls to be saved circa ~150k. You make the team or it's goodnight. But how that grade is attained and what one should do to prepare.... both churches espouse the same basic tenets. JWs are just a bit more rigorous in terms of determining who made the team or not, and the alternative for those that don't seems entirely enjoyable so...

If you're of a particular church you're probably acutely aware of the differences and that's a point I have no appetite to contest. How it factors into distinctions in preparedness doctrines emanating from each church? Not much I reckon - They're both putting out a good message and I'm, irrespective of personal beliefs, comfortable taking on-board the core messages of both churches. They are doing good works and that is to be lauded!

tl;dr you can take or leave interpretations of the rapture; the idea of squaring away a few bags of rice and some tea lights has universal value to even the ungodly masses. Everyone wins, and there's nothing to be gained taking up a mantle of chief faith-questioner, I reckon :)