(wrings hands while doing muaa ha ha laugh)
Congrats man, sounds like you really took to it quickly.The MQX quad is very neutrally stable with the AS3X system on board. What that means is that once you set the heli (or quad in this case) into an attitude, it will simply hold that attitude until you correct for it yourself. It doesn't have the self correcting nature of the 45* flybar of the MSR and SR 120. And when you send it in a direction, it will hold that heading until you tell it not to, you have to cancel / correct each movement. The quad flies more like a flybarless collective pitch heli than anything else really, a lot of that due again to the AS3X system that is also used in the MCPX and now the Blade 450X (it's just rebadged Beast X flybarless tech). And with 4 motors on board, it's very fast and responsive when you send off in any direction as well, it's gotten away from me a few times in the house.
Personally, my advice having completely quit on helis once before. Buy a good TX instead, like a DX6i so that you have full control over the heli you have now. That way, you can tone it down using dual rates and expo when you start flying circuits, etc. Then as you progress, you can move the swash links to the longer ball studs, turn up the dual rates in the TX and really let it rip outdoors. Plus, from here on then you can just buy the bind n fly stuff. The SR 120 is a very durable little bird, don't be scared to crash it outdoors once you get to that point. I've drove the one I had in from 30 feet up, straightened the blades and went again. It's a fantastic heli for it's intended purpose IMHO, that's why I owned one, and why I've since passed it along to a friend wanting to learn without breaking the bank.
Let me know if there's anything I can help with. I always enjoy having other rotorheads around.