Several years ago, I installed a Miter Slide on an Incra LS 17. Using just odds and end hardware I had available the resulting mounting turned out extremely effective. Runout the last time I measured full length of travel was somewhere around 2-3 .ooo's IIRC. I wasn't really happy with the OE sled provided by Incra. This was more of a personnel preference than a slam on the Incra sled. I felt that the OE sled had the potential for excessive play at the worst possible times. So I went with the Jessem.
The Jessem miter slide is extraordinarily well built as mentioned earlier. The thing is as solid as a rock, no if's, and's or but's about it. It delivers exactly as advertised. The only down sides are the price (these are not cheap) and limited mounting options. These are pretty much designed exclusively for the Jessem fence systems. It can be mounted on other fence's, however it may take a bit of grey matter.
In use, when properly set up, it's smooth, accurate and a joy to use. I still have the OE sacrificial fence it came with. Choosing to just replace the OE board with a sacrificial board when in use. I've found that it excels when making box joints, dovetails, double dovetails, trivets etc. in conjunction with the incra LS fence. None of these designs are exclusive to the Jessem Mite-R-Slide. The slide more or less aides in the execution of the process's rather than provide a unique twist on them.
"..... limited only by imagination"
"Just smile and wave boys, smile and wave"
Skipper the Penguin