thank you for your input. I decided to make the purchase. I tried flying the mcx in my living room and it was pretty cool. I could fly it in circle and slowly make the 8. However, I think I need to adjust the trim a bit or something since it doesn't seem to hover in one spot. As far as batteries, the guy gave me Tenergy Lipo Batteries 3.7v 130mah, but the batteries are a bit fat and can't fit in the mcx or msr. Anyone ever used these batteries? They seems like they would fit if you cut off or trim the flaps on the side. Did anyone ever get those Tenergy batteries to fit in their mcx/msr?