Just had a listen...
In my honest opinion I think there are a few things you could do using the stock plugins within logic to improve your mixing / production - as well as improving your arrangement approaches
I don't mean any of this to sound harsh but I agree with MIHKAY that there are things you can immediately improve on without spending a penny
The following examples are truly meant to help you improve as I wouldn't normally be so critical but I think you could be sooooo close to getting a really punchy, pro sounding, mix with a few tweaks and different approaches...
The whole mix sounds a little "distant" to me
There are lots of techniques you could use with what you already have at your finger tips - eg using compression and EQ to bring things forward and use EQ and reverb to push things back in the mix to add some depth
I also found the mix very narrow with everything down the middle - I think you would get a more engaging mix if you panned things around the stereo field and even move things around using automation as the mix progresses - eg pan the little guitar fills to one side, bring the guitar into the middle for the solo, then pan it back to where it was
Your current mix seems to be lacking any bass instrument? - I think I can hear one but there is certainly something missing in the low end
If you can get your kick and bass mixed well together you will be half way to a solid mix
I also found the high end quite "harsh" and the cymbal crashes were a little "thin"
There is a constant ride cymbal that seems to be "washing out" the mix - just replacing this with a hi-hat would really tighten things up and make the mix clearer
You could also play with other techniques - eg add some side chain compression to your pad to give it some movement and clear a bit of space in the mix to let the bass through or try some parallel compression on the drums to beef them up a bit but maintain a natural sound
What about triggering a really low sine wave synth that only plays when the kick drum plays to sure up the low end
These are all techniques that you can probably do with the stock logic plugins (I am not too familiar with logic)
I can tell that you do have an ear for mixing but I think you could get an overall improvement by investing in some education - if you have the time I would recommend not paying for any new plugins but try out Groove3 and check out some of their mixing tutorials:
https://www.groove3.com/ There are 35 videos dedicated to logic (
https://www.groove3.com/logic-training-videos ) as well as loads of "general principles" videos that are always helpful
I ALWAYS learn something new and helpful from watching tutorial videos
To get a pro sounding "pristine" mix you really need to start off with good source material
What are you using for your drum and piano sounds?
If these are being played live a recorded via microphones you will need to start with mic choices, mic placement technique, dealing with phase issues, dealing with the acoustics of the room etc. etc.
You may be better off getting some good VST (virtual) instruments that will give you an instantly good sounds - eg having a good drum and piano VST is always handy
Last (but certainly not least) how is your monitoring set up?
Have you tried playing a test tone in your room that plays all the frequencies at the same level
In your room you will likely notice that the volume will appear to increase and decrease at different frequencies depending on the acoustics of your monitoring environment - you may be amazed by the results
There is an example of a "sweep test" here:
http://www.genelec.com/audio-test-signals Your second best investment (after education) may be some acoustic treatment to improve your monitoring
If your room over exaggerates low end you are likely to mix with less low end, which will then be lacking on other systems/environments (or vice versa)
Acoustic treatment is not as sexy or as much fun as a new plugin but has the biggest potential to improve your mixes
But having said all of this it can always be fun to get a new plugin so I can recommend lots of fun stuff when you have a clearer idea of what you are after