I prefer Harrahs. Yes, I know it's away from the boardwalk, but if it's not hot when you go, what does it matter? It's very cold to walk along the boardwalk in the off season.
I would rather stay at Harrahs, which has a fabulous indoor pool, great drink service, lovely rooms, a great buffet, and friendly employees than to stay at the Showboat, which is rather known for the daily shuttle buses of the masses to play. And right out the door is a free shuttle to their other properties on the boardwalk, if you are so inclined. Although if there is a horrible line for it, I just pay the 2.50 and ride the city jitney bus.
Have fun and please post a trip report. there are so few of them these days...