You have already had several answers here, but let me put my two cents into this question as well. Right now due to our market conditions softening and inventory levels rising this is causing our rental market to soften as well.
That being said if you decide to rent, you will have to consider several things. I'm not sure what your purchase price was on your condo, which building you are in (amenities or none) and not knowing that makes it difficult or impossible to say what type of a realistic return you can be looking for.
One thing that is working against you when it comes to rentals, is that many of the new rental buildings and older ones are offering incentives and concessions to renters. One month free rent or more, some perks, etc.... Thats something you will have to consider if you decide to rent it out.
When it comes to Condo sales, Battery Park is not a quick moving area. If you were to sell your apartment, will your price be competitive with the LEED buildings which are going up? Many buyers look for a resale property on a new construction to avoid paying Transfer taxes which can work in your favor.
Someone here already mentioned, with you being away in another country it will be very difficult to manage your apartment on your own unless you get help of a managing company who can take care of your apartment.
If you were to go that route and rent, I work for Prudential Douglas Ellimand and we manage more buildings in the City than any other R.E. firm which can be something for you to consider.
If you decide that selling makes most sense to you, in my personal opinion don't go with a small firm that nobody knows. Choose a large firm. Douglas Elliman is the largest firm in New York with most amount of listings and we bring sellers highest amount of exposure for their properties. In todays market for your apartment to sell you need two things going for you (Correct Price and Exposure). One year ago it used to be location location, now its price and exposure.
You purchased one year ago, and I'm not sure how much your property has appreciated over that time if at all. I can run some comps for you to see how many properties are on the market currently in Battery Park and how many have sold in the past 3 months and how many are currently in contract.
One last advice, don't try to sell or rent this on your own, you will just waste time, energy and money. Do it right from the start, capture largest pool of buyers/renters, move to Europe and only look forward to good times.
Hope to hear from you Laura
Best of Luck