It looks like you're getting the right amount of penetration (as stated already), but I would continue around the corners. Also, as you can see from flux welding, it creates a lot of spatter. You don't want that spatter in your weld because it weakens the weld. If you happen to stop a bead, you need to chip off the spatter and wire brush the whole weld clean before you start again. That's where a angle grinder with a wire brush disc is really handy. When I'm MIG welding (flux) I also use the spatter spray you can get in an aerosol can. Makes chipping off the spatter not much more than just a wipe with your chipping hammer.

As my instructor once told me, it's better to weld a little hot than a little cold. At least if you're too hot you'll know it right away. So I usually kick my amps up a touch more than many people. Have you seen/found the dot yet? :)