I have some of those epower 4500's they are from the same manufacturer as the ep's. The samples i got were o.k. could not compare to the ep4600's or ib4600's. They have slightly hieghr IR overall and are great for club racing but not for high level competition racing.
www.skyrocketracing.com quality RC gear!
http://www.rctech.net/forum/racing-forum/555071-2011-skyrocket-invitational-blue-diamond-raceway-october-15-16-a.html <- Great race!