I debated a long time before picking up the Ridgid R4512 TS earlier this year. I decided to go for it even though it had some shortcomings - the price was too good for me to pass up. So far I am happy with it and I wanted to share the modifications I have made so far to make this tool even more useful for me.
Here are a few photos showing the router table I built to replace the right extension wing. I followed John White's design featured in Workshop Solutions from June 2011 for the table top. I made custom wooden shelves that attach to the saw rails front and rear to hold the table up. I used 3/4" MDF for the top edged with maple and covered with plastic laminate. The structural members underneath and the rail shelves are made from Baltic birch. The rails on my saw had t-track on the underside which made it easy to bolt the support shelves to the rails. I also added some 2" square legs to the extension made of pine for stability. The design by John white features a dust collection box in the fence and a hole in the table to allow dust collection from above the table and from the router itself below the table. I added a miter slot to the table and I also plan on adding a t-track parallel to the miter slot for mounting feather boards.
Dust collection ports viewed from below the table:
Here is the fence design I used. It is a hybrid of the design used by John White and the one developed by Norm Abram. All 3 of the rectangular fence pieces can move laterally using t-track mounted in the back of them. They all bolt to the main fence face with 1/4" bolts and star knobs. The second picture shows the back of one of these fence pieces. I added 6 screws to allow for fine adjustment for squaring the fence to the table. The entire assembly bolts to my table saw fence.
I also added a high fence for my table saw that allows me to mount feather boards and other jigs using t-track. The high fence bolts to t-track in the top of the saw's fence.
Here's a shot looking down on the entire fence assembly:
Finally, I recently bought a used jointer on kijiji and the guy gave me a cast iron extension wing from his damaged General contractor saw. I made some minor modifications to the bolt holes and it fit perfectly. Here it is installed as the left extension wing on my saw.
Thanks for looking. Appreciate any comments/feedback you may have. In the end I have a full cast iron top and a really useful router table setup that allows me to save space in my small basement shop.