I recently purchased a home with Pella sliders in it.... however it was their upgraded unit from Doors In Motion. www.doorsinmotion.net They sent their pella door slabs to them and had doors in motion build their high end automated sliding patio door with a pocket door!!! I have now a 16' wide by 9' tall opening and at the touch of a button it parts and vanishes into the wall!! It is amazing. I dont have mine video'd yet, but if you look up doors in motion on you tube I found a few of theirs. I see on their web page they actually can make curved track units and 90 degree corner systems as well!! It makes me wish I would have saw this before I started building our home!!!