1.5 times its mah rating is fine(1.5:1 ratio) on most non-nano lipos. i.e. 6amps on this 4,000mah pack. If it gets hot then back off. Most will not get any warmer than if you were charging at a 1:1 ratio.
These batteries are perfect. They are exactly as advertized and they are great quality. It really is unexpected for the price. I can't think of anything wrong with it. Other than if you plan to put a Deans connector (nylon t-connector) the wires are a beast to solder because they are so thick.