Tbh I not really heard of the overland lipo's so can't really comment for or against, I personally use HPI Plazma 5300 30-40c. Never had a problem can easily get 10 mins racing with a 7.5 motor plus plenty more after, if ya shop around they have come down slightly to around the £60 mark, I got mine last may and they were £78.99. Still got plenty of go in them.
Hope that helps
