Yes, most, if not all OEM crankshaft pulleys have a dampener on them. Removing it does not unbalance the engine, it just reduces the amount of vibration dampening available for the crankshaft.
I've never seen an underdrive pulley with a dampener on it. I've also spoken with engine builders who have rebuilt engines after thousands of miles on them with an underdrive pulley and have seen no evidense of any damage done to the engine. I've personally used them on a couple of my cars without any problems.
If you are really worried about wear, do an oil analysis now to get a 'before' shot. Then, install the pulley and do one again when you change your oil next. Send it in for analysis and they can tell you if your crankshaft/journals/rods are wearing.