Chinese parts ruining good American parts.
It's worth mentioning two things here:
1. Unless the 4L60E gets hot enough to boil out any condensation on a semi-regular basis, it is likely that you may get some water buildup inside the transmission. This is especially true if your 4' vent harness isn't installed. There's a reason GM made it 4' - it's to keep the trans from sucking in moist air every time you get on the gas or the transmission cools down.
2. Coolant will cause the 4L60E's clutch material to delaminate, so you really don't want to let any sort of coolant leaks go. If you see oil in the coolant or a funky look to the transmission fluid, attend to it immediately. And yes, having internal radiator coolers is a good idea, for reasons that have been discussed in other threads.