An old thread, but I have just made my first two splices in dyneema. I can confirm that it is really quite easy and yes, it did come out shorter than expected, by about 5cm, but that just means a slightly longer lanyard on the forestay. I used the instructions for forming an eye splice from a gliding site, which does away with threading the full length through, but still has the load tightenting the eye.

http://www.keepitsoaring.com/LKSC/Downloads/dyneema%252Fspectra-splicing-manual.pdf

I also did it just using a normal Swedish fid. When I buried the long tail, I just did it in two inch sections, coming out the side of the braid each time and then going back in. Hard to describe but easy to do. I have posted some photos on my blog at
http://daisygracebaycruiser20no1.blogspot.com/2012/02/dyneema-forestay.html