My HBK2 that I got in May came from the factory with digital servos - so the newer ones already have those. I agree that they will make no difference and that you should check the Rx antenna, power, and clean the stock Tx as described above.

Also make sure you're flying in an area that doesn't just have a lot of RF interfearance on the frequency that you're using. A poor quality signal could make the heli respond slowly I would think... Seems like something to consider, since it works better when you're closer to it. If it is a signal problem, get one of these Dx6i Tx and Rx combos: http://www.ushobbysupply.com/product...63020130d54fb0 Should eleminate all RF interfearance (spread spectrum, frequency shifting - will work around other things that could interfear). The programable Tx can also be set up to make the helicopter easier to fly too!

Good luck!

Dave