So new to the Mac Forum. Forgive the long post. Looking for some advice. I have an IMAC 27" 5K Late 2015 desktop. Computer runs very slow. Fan is load. Pictures don't sync quickly (take about 24hours) iMessages are slow to appear. Desktop files are slow to sync even though everything is synced to the cloud. I have spend hours and months with Tech Support to get this all resolved. Never fixed my problem. I have a MacBook Pro (2017) that works great. I am wondering if I should purchase a new IMAC or if I should purchase a docking station and use the MacBook Pro as my desktop. I have two external 4K monitors that I could easily hook up to the docking station if need be. Any advice