I have one of the slightly older Fujitsu ST5010 series slates and my experiences have been nothing short of excellent. The fit and finish on the ST series is excellent and to date I have had zero problems with it.
The primary difference between the two systems that you have detailed is that one is a convertible while the other is a slate i.e. the Acer has a built in keyboard while the Fujitsu does not.
Either one of these would most likely fill the role of presentations to clients fairly well, so the choice will most likely come down to the following criteria.
-Form Factor (Slate or Convertible)
-CPU (Type and Speed)
-Screen Size, composition, and viewability angles
-Graphics Processor (the Acer is available with a 265mb GeForceGo 6200)
I would list out which options are available on each system and decide which ones you require most. Somewhere in that process, it should become evident which system is going to best fit your needs.
Hope this is helpful,