I am very willing to go to a new better workflow, my point was that this is a viable workflow, and for good or bad, the one I chose to use for all my images on the 1280. My concern is that the image will look different if run through another workflow and again all my images in each size will need tweaking to print correctly on the 7890. This would be a phenomenal amount of work.
Very nice photography, Scrinch. I know that change can be tough, but I think you'll probably have to do it. Your current workflow has tied all of your output to one specific printer -- which is no longer available. Any new printer, with different printing technology and a different inkset is going to produce a different result from files tuned to work with a 1280.
When you use a color managed workflow, rather than a printer specific workflow, this problem largely disappears. Using a properly calibrated monitor and proper printer/paper profiles with Photoshop managing colors will produce much more consistent results no matter what printer you use. Everyone is recommending this workflow because in the long run, it will SAVE you work; especially if you switch printers.
One last thing I'd like to point out. Adobe has changed their upgrade policy to 3 versions back. So if you're using CS2, then CS5 is the last version eligible for the upgrade price. You'll have to pay full price for CS6.