Either one (Do or X100)would be an excellent start, I'm more in favor of the X100 but the Do(.60) is not too far behind. I think the Do might be a little easier to hover but it lacks the smoothness and tracking the X100 has. The Do will handle most 3-D but needs modifications for strength and 3-D flight. The X100 is far better design,easy to work with,no modifications needed and light wing loading plus the hardware is the best. If you have one of these and a simulator,you will cut down the learning curve time a lot. Either plane will require a mixing radio to get the most out of them,I have used mostly Futaba for almost 20 yrs now,the 8UAF and 9C are the latest 2 I've had. The 9C is best IMO,no need to pay $1,000+ when you get more radio than you can use with the 9C. You could get by with the Saito 100 in the Do(60) but the 150 is best for the X100. The X100 needs a heavier engine up front, I love the OS 1.20 AX but the Sa1.50 will do it. I had a .46 UCD but didnt like it mainly because it was too small, I'm beginning to believe the larger the plane, the easier it is to 3-D.