I'm considering going for my Level 1 Certification and I was going go with either a G-Force or Sumo from AT.

Problem is I heard mix reviews on both kits. The Sumo seems to have issues with the piston being too large in diameter and binding up depending on the weather conditions and the G-Force has issues with the ejection charge on the required motor not strong enough to blow the nose cones off. Has anyone who has built these kits experienced this problems..if so how did you overcome the issues?

I'm considering maybe just buying Modern High Power Rocketry - 2nd Ed and seeing what I can find in there and bypassing the kits all together and building my own rocket?

Any feedback is appreciated.