I'm no professional. I don't consider myself ready yet, I'm not promoting myself because I'm just a student when it comes to music theory, mixing, and composition... 99% of the people on this site are still learning wayyyy more than they are teaching others. So take my 2c and everyone elses with that in mind.
I liked the mix that you "mastered" more. Mostly because it was louder, and when you put them together like that anyone is going to pick the second half (mastered). But thats not mastering, thats mixing. Mixing is everything to do with your sounds, volumes, fx, etc.. mastering is basically formatting the project to a widely accessible medium (cd, mp3) and polishing the track. People get clowned every day on here for using the term mastering, I did before I read up on it... so start reading! the stickied posts in recording,mixing, mastering are a great place to start- but they should only be the start.
As for the actual song (mastered). Its very catchy, props. I'd say halfway through a 'verse' add a small rhythmic instrument to give it a little variation. The samples are clutch though, like them a lot. I like my hihats a little lower in the mix, subtle is effective with those, especially when they are crisp and have their own notch in the mix. I like that you boosted the synth sweep sounds in the second version (maybe too high), but I would like to hear a little more of the background melody in the mastered (samples with the keys). maybe eq the piano sample to give it that bright edge. Also, on bars 3 and 4 when the sample hits with the kick, there is a real raspy saxophone-like sound underneath it all, try to bring that out itll sound dope.
Your up for a long journey if you dont know about mixing... but from this mix you definitely get the idea. Good producers have good ears and thats half the job. listen to what your song needs. When you listen to those two inline like that, the benefits of your mix are easy to spot. its louder and brighter, sounds more commercially viable. The negatives are always hard to hear especially after you did the work. For example just glancing at the soundwaves while i listen, the kicks are at the same level in both mixes. In the second half the rest of the mix is pulled up, and that takes away from the swing, the swagger, the call/response feel of the track. Now before I said I liked hearing those sounds louder in the second version, but I also miss the swagg. Here's where mixing separates the men from the boys.. make all of the "good" frequency ranges for each instrument stand out, while keeping the less appealing tones down. Dont just hit the volume on an instrument, hit the eq and you will see huge benefits. Its way better to cut out Freq. ranges than to just boost the good ones, trust.
As for mixing, do the knowledge first. Use tools in small amounts and for a purpose. And always have a song to reference against, sometimes the original plain sound. I can't tell you how many times I've mixed a beat, or mixed vocals over a track... spent 4 hours playing around with knobs, then I take a break come back and listen and it sounds like pure garbage. Moderation is key. depending on genre of course, some 'tards like autotune, go figure...
I'm not afraid of dying, I'm afraid of not trying. Everyday, hit every wave like I'm Hawaiian. - Jay Z