Do you guys feel it is good to instantly remove the heatsinks and apply new thermal paste to the chips?
I am unsure of the quality paste used from manufacturer but I highly doubt it is premium due to production costs.
I have been running both of my Ant's OC'd to 500 GH/s and 490 GH/s and both temperatures are well within normal ranges and all chips are stable and hashing with no X's. One of them has been running a few hours as if you look up a post or two you'll see where we came up with the newer smaller incremental frequency steps, and that is the one running at 490 GH/s up from the 237.5 clock which was in the 470-480 GH/s range, while the other has been running for 72 hours at 500 GH/s.
Highest temperature reached by any miner is 44C, while averaging 40-43 C in use, so I would say replacing the thermal compound is unnecessary.
That being said, if you do decide to go ahead and upgrade/replace the thermal compound, do not use any compound with Silver in it as it is conductive, and make absolutely sure that whatever brand you decide to go with DOES NOT CONDUCT ELECTRICITY - YOU WILL FRY YOUR ANTMINER!!!!!