So, first flight this morning I did with CG at 30.7%. Perfect day with no wind at all. Rotation was pretty heavy on the stick with forward CG but after that everything went back to normal. Level flight was like on rails. Didn't pool to the right or left and hold trimmed altitude rock solid. Airplane was flying hands-free!!! GPS speed test 4-direction at 3000 ft was 87 MPH at 5400 RPM. I found myself thinking that I really like my little flying machine. Sure, would be nice to get a little faster, but when airplane flies perfect like that, then you start thinking that all it needs really only drag reduction with engine cowling and so on. So, I landed, removed 45 lb from the front and went for 2nd flight with CG at about 34.4%. Nose was much lighter during rotation, but immediately during climb I was sensing difficulty trimming for same speed. It feels like pretty windy day with updrafts and downdrafts and you end up compensating with stick all the time to make airplane to do what you want. Level flight was not any different. No more hands-free anymore. Absolutely impossible to trim for altitude hold and constant speed. Airplane starts ballooning up for 5-6 seconds by 300 feet which resulting in dropping RPM. Then by itself starts descending with engine RPM going into red zone for another 300 feet or so. In addition to that if you don't compensate with your hand it will drop the wing and start entering into spiral. GPS speed test was much harder to do and as far as I can tell speed stays the same. I made a conclusion that I will be flying with ballast and removing it every time if I end up going with a passenger. Question I have, is why CG movement by only 3-4% have such a dramatic effect? Is this because my horizontal tail to small?