I replaced all the halogen lights in our coach about two years ago when word first came out about the oversupply of LEDs at Kaper II in Kelso, WA. I called and ordered 75 of the 3" LEDs from Leslie Charette. She indicated they had over-ordered and the inventory was taking up too much shelving space. Thus, they were having a "fire sale." I also needed to purchase some blade connectors at Home Depot because the new LEDs came with their wires bare-ended. I only needed 57 LEDs, but ended up giving a Beaver-owner friend the others so he could change his out too. The LEDs are a brighter and softer light than the original halogens. Their power usage and heat are almost un-noticeable - only 1.2w compared to 10w and the lights' diffusers barely get warm. My total cost was just over $200 for 75 LED lights, shipping, and the blade connectors. I spent three mornings changing out all 57 halogens to the LEDs.
I would rate this project as a significant and inexpensive improvement to our coach.