Anthony,
The Universal Cleaning Set (cat 497 702); the Tradesperson/Installer Cleaning Set (Cat 497 700) ; and the Workshop Cleaning Set (cat 497 701) all include the 36mm AS x 3.5m (11.5') hose.
Way back when I had only owned my first TS55 a single day, I went back to my favorite dealer on a Saturday because that was when a bunch of experienced woodworkers hung out, exchanged ideas and ate snacks.
A fellow who had been using the predecessor to the TS55 made two suggestions: buy the accessory side plate and always use a 36mm AS hose. In addition to collecting dust more effectively, his experience was that the slightly stiffer 36mm hose hangs up less often on the rails than does the more flexible 27mm hose which comes with the dust extractors and is needed with sanders and a few other Festools. This fellow also said that for breaking down 4 x 8' sheets, the 5.0m x 36mm AS hose was more efficient, while still providing great dust collection.
My dealer had all of those sets good in stock. I decided on the Tradesperson set (cat 497 700) because I needed to clean the carpet in the workrooms in my condo. I added the Plastic Turbo Suction Brush (cat 450 644) for really great carpet cleaning. My dealer was generous to swap the 36mm AS x 5m hose (cat 452 884) for the 3.5m hose in the kit, charging me only the difference. Sort of like paying the difference to get a longer or Holy guide rail with a saw.
That was January 2006, before the Boom Arm was available in the USA. I am sure I saved a lot of time by using the 5m hose. With a boom arm I use the 3.5m x 36mm AS hose, because the boom needs to be fairly accurately positioned and the longer hose defeats the benefit of the boom arm.
Speaking of 36mm AS hose, I buy the 36mm AS x 7m hose so I can cut the shorter hoses I use with my Kapex without waste. I find the ideal length length for a Kapex hose is 2.3m which is 1/3rd of the 7m hose. 2.5m,which is 1/2 a 5m hose is in my opinion too long.