tess-
I've been a Financial Advisor for 16 years and counsel clients on purchasing this coverage regularly. UNLESS your current job is considered high-risk (police, fire, moto-cross racing etc.), I would NOT purchase LTCi but instead focus my premium dollars on good quality, solid, "modified own occupation" disability insurance. If you DO have a higher-risk job, it may be worth it.
At your age, your ability to earn an income is by FAR your most important and largest asset. It eclipses your car, home, or other personal property yet we have insurance on all those things.
If your occupation is highly specialized (surgeon etc), then I would recommend "true-own occupation" coverage (own-occ) which would cover your current occupation REGARDLESS of what else you may be able to do if "disabled" (think of a surgeon who loses a pinky: he can't do "his" job -surgury- but could still teach and earn an income).
The old question to ask your self is: "If you had a machine in your garage that churned-out $50,000/yr (or whatever your earning potential is), what would you insure it for?"
For reference, assuming you're in good health and in a "typical" occupation, it should cover roughly 60% of your pay monthly and it will probably cost roughly 2-4% of earnings.
NOTE: Be careful of coverage you may have through your employer- they typically come with VERY poor "any-occupation" language that says the insurance company only has to pay if you can't do ANY job- not just your "own" job.
Good luck!