I haven't seen your old animations, so I can't tell if there's be any improvement for you or not :/ Looking at your animation, it seems you are fairly new to Pivot Animation, or at least new to animating in the Pivot community (Your style is similar to that of my own when I started out)
The main thing you are in need of at the moment is more dynamic movements. A common piece of advice is that during any main movement, you should move every joint in every frame (unless he's standing still, and the movement is a tiny one). You might not know exactly how this is meant to be done, but it's not too hard to figure out when you factor in some simple physics regarding momentum and balance. For example, if you have your stick lift his right arm forward, realisticly he should account for the shift of balance by changing his stance slighty. This can be done by moving his left foot back a pixel or so, maybe bending the elbow joint on his left arm just slightly. Remember, every action has a reaction ;)
It's also good to use nice poses. If you want to be a good animator, it's important to keep all of your stickmen's arms and legs on realistic angles (unless you are deliberately making something silly, which is fine if that's your style). If on any frame your stickman is in a really weird or unnatural position, then you know you are probably doing it wrong. The best way to keep your poses in check is to make sure that the beginning (and ending) poses for a movement looks good. If the starting pose is bad, it'll be hard to make a good movement.
You might have people tell you that you need to "Ease More". While it is true that Easing is something most every animator must know how to do, it can actually impede the quality of your movements if you focus on that before you learn poses. Based off your animation I would Rank you as Low Beginner. You've got a long way to go yet, but remember that every Elite started off as you are now :) heck, I was a noob for a good two years before I started getting good. I'm sure you could become an amazing animator if you put your mind to it! I hope this advice helps :)