I recently upgraded my DJI F450 to a Team Black Sheep (TBS) Discovery frame. It felt heavier and less nimble, so I also converted from 3S to 4S packs. The 4s conversion required smaller propellers and I found a new line of multi-rotor props from APC at Aero Micro. I bought 9×4.5 for the quad and 10×5 for my tricopter. They are fantastic! Most of them are perfectly balanced out of the bag, I don’t think I’ve had any props like that. The injection molding tool must be brand new, buy your props now before the tool wears!
I also increased my pitch, roll, and yaw gains to get snappier response. I may have put the TBS disco in a tree due to sluggish response from a “BANK RIGHT!!!” input. Things also feel snappier with the smaller 9″ props. Here’s a video of the flight, I have to say I think the quad is flying better than it ever has with the new upgrades!