Anyone using the Windtunnel Lipo 4800 pack for racing ? and how are they?

I've am using one in 13.5 dirt oval racing and I love it so far...

What balancer and charger are you using thanks

I am using a GFX and the checkpoint balancer. I balance the pack the first time I charge it on race day, and then just re-peak with the GFX for the rest of the day. A buddy I race with does the same thing, and we've had great results with these packs.