You are running version 1.5.1? With that version our test units rarely experience drop outs anymore, and it usually reconnects pretty quickly. Our latest release contains TI's latest firmware patch that gets pushed to the CC3000 module when you load our latest software, seems to have addressed a lot of issues. We have our test units close to either the WiFi router or a range extender though which guarantees good signal strength. When I move my unit too far away it will connect (after taking a while) but drop out quite often but at that point my cell phone and laptop are usually having issues as well.
There are things that you can do to minimize the connection loss issues such as placing your unit really close to your WiFi router. If that is not an option then you can look into purchasing an inexpensive signal repeater / range extender. There are also known issues with different types of routers that we documented in one of the very first threads in the forum. A search for Spark Core TI CC3000 issues also comes up with some posts that they did with similar content on how to get a better connection.
Unfortunately we will not, as of this time, be offering any sort of swap out between the devices. We are planning on selling the new controller board separately from the rest of the unit as an option, so if you did want to upgrade you could purchase just that single board.
I know this isn't what you wanted to hear and I apologize, hopefully with the latest software loaded and the above suggestions on WiFi router/repeater placement we can fix or minimize the issue.