Lithium batteries have a early voltage dropoff. The silver-oxides hold voltage till the end. With some of the OM bodies, the lithiums will drop below the needed operational voltage rather rapidly. In fact, with the OM-2S and OM-4 (original), this point of insufficient voltage can occur in hours.
The OM-2n is a pure pleasure to use. It handles like a sports car in comparison to other cameras.
The lenses, even if they are the older silvernosed variety, should be outstanding performers. In fact, many of us actually prefer the early-mid formula of the 100 F2.8 to the later versions. The 50 F3.5 is one of the best macro lenses of any make--only superceded by Olympus' even better macro lenses.