MacBook Pro Early 2015: Sleep Wake Failure
The next time you have an issue, run sysdiagnose by pressing the key chord for it or manually from terminal and then open a support ticket with Apple. Much of the diagnostic information in console.app requires one of two things to be useful:


Access to Apple's source code and internal support documents
Access to a large volume of logs from dozens (or ideally hundreds or more) of Macs to use a tool like splunk to collect and analyze various logs to identify patterns of error messages to trace back issues like this to root causes.


In the mean time, use old-fashioned pen and paper to make a note of the wall clock time when the Mac is slow and look at Activity Monitor / top and perhaps collect one sysdiagnose each time you notice the Mac being slow. Once you have 10 incidents, you might have enough data to know what processes are making your experience poor and determine if your slowness is related to:


CPU constraints or overcommitment
Memory pressure
Storage issues
Network dependancies


A good place to start on that monitoring is using top or vm_stat to run when before you notice the slowness and then review for data once you notice that the Mac has actually slowed down.

OS X: Memory usage freaking me out

I would also write down what you wanted to do and what other apps were running when you notice slow downs. This will come in handy to identify if you can simply adjust the workload or need to make other changes to achieve better performance.