I say go for it. At the beginning of this year I had to switch to US Airways because they had the only direct DCA-TPA flights available. Even though I've been status matched and have been upgrade probably > 90% of the time, my experiences with this inept organization has actually caused me to fly Delta whenever humanly possible. I have 36 segments on US YTD, but will hit platinum on Delta this coming Sunday.
Why? Because at least with Delta I see progress. There are still problems, but they actually seem to care that customers are complaining. Even though I haven't been upgraded nearly as much on Delta as I have on US, I just cannot stand by a company that constantly spits on its customers. I have made it a point to book on Delta exclusively until the end of my project despite the layover in ATL. I say go ahead and jump ship while you can.