That depends a lot on what you are after... If you want to get into FPV, a good idea would be an FPV starter system. If you want to get into scale planes like warbirds and such, you could get your first warbird. If you want to get into acrobatic or pattern flying, a plane of that type will be good (as long as it's durable). If you're into multicopters you could get a small quad to learn on. It all depends on where you want to go.
Thanks for your reply, I think my next step is acrobatic flying not 3d more like real world aircraft in an air show, no weird maneuvers that a real aircraft cant do, just to learn real world aerobatics to show off an aircraft.
So with that in mind what do you think is the next step from a bixler? for a pilot that can fly and land Bixler 10 out of 10 times in one piece?