With perfect maintenance they'll last pretty well. The early years had some teething problems, but 94 will be OK. Of course these engines are more complex than the inline-4, so check the maintenance records carefully - like the V6 the temptation to skip bits of maintenance are there...

With abuse, forget about it. Tolerances are much tighter, so regular oil changes are more important. These are all-aluminum engines, so use quality antifreeze rated for aluminum engines (which is most antifreeze these days). Maybe most important of all, don't skimp on timing belt changes, and carefully check the tensioner pulleys when you do the t-belt. If in doubt, change. Unlike the I4 the I6 (and other white block engines, like anything used in the FWD cars) these are interference engines, and a broken timingbelt will lead to expensive damage.

Also check the rest of the vehicle: They're full of electronics, and make sure everything works as it should, and consistently. The wiring looms on these are large, heavy and complex.

Bram