Just wanted to post in case anyone was interested. I was setting up to make a couple of large sleds for my SS Compact saw, so I purchased both the Woodpecker and the Incra Special Edition Miter Sliders, but ended up using the WP bars. The Incra bars use 3 plastic washer adjusters on one side of the bar and 3 more plastic washers that are not adjustable on the opposite side. The WP bars use 4 leaf springs along one side that require no adjustments for a perfect fit. My concern with the Incra bars was that the nylon washers needed occasional adjustment, so that meant either removing the bars to adjust or drilling access holes on the top of the sled. Also, those adjustments might throw off the sleds 90* setup and I didnt want to risk that.
The WP bars work great. They fit securely, but can still slide with minimal effort. They are 25.5 long, however since my sled is 29 long, I added short wooden bar-ettes to keep the sled tight throughout the sleds capacity. I used quarter sawn maple for the bar-ettes. With the bars mounted, I used William Ngs 5 cut method to get one sled to .0001 over a 24 cut and the other sled to .001 over 24. The good part is, these sleds should remain accurate and snug in slots regardless of occasional periods of high humidity. By the way, I used a great suggestion here to mark the mounting holes for the bars. I got some pointed 8-32 set screws, put marker on the points, then screwed them into the underside of the mounting holes until they made contact with the sleds underside. Worked great!