I will try and be clear about this as I find the info isn't all that easy!
The SEBO BS36 uses a twin motor similar to the older 360. They're built solidly and have quiet motors, also easy to unclog and great cleaners for carpets. They weigh 8/8.3kg but they come with a stitched in 10m cord through the handle against the single motor run SEBO 350 Evolution which weighs 8.3kg and has a 12 metre removable, replaceable cable.
The Evolution series REPLACES the older 370/470 Comfort uprights which don't have removable cables and run on 2 motors. They do however have tool storage on board and like the Evolution features both a long crevice tool & a separate upholstery brush tool. Certainly if you can source a new one you might find cheaper cost prices!
My old 360 is being used at church at present and it has found favour with others. I find it more useful to use when I detach the power head and just carry the bin and suction motor unit vertically with me when cleaning seats or pews. I end up laying the machine down or propping it upright and use the suction hose to gather up sawdust mess from the seats.
It also has a Sebo Felix twin tool holder on the front of the handle where cleaning tools can be stored. However the tool storer itself is vulnerable and probably only really suitable for those with gentle hands if they are going to store tools on it!
The BS36 & Evolution use the same type of dust bag which tend to be cheaper as they are paper based rather than synthetic disposable dust bags seen on the X series, which the 370 also uses.
Either way at the end of the day, consider your purchase prices and your operatives who have to use the upright. If they are used to simplistic controls, I'd pick the BS36 over the Evolution 350. The BS36 comes with one cleaning tool but ONLY A clip on the front to store it.
If the staff are liable/known to break cables, then its the Evolution 350 which has a replaceable, longer cable; it also comes with two cleaning tools which store on the back of the machine. [this post was last edited: 8/15/2016-18:31]