I have had a Festool Rotex I50 for the last 16 years and I LOVE it. Why, you ask:
The sander costs a LOT but lasts FOREVER,
The sandpaper also costs a LOT but lasts a long time,
Very little vibration,
Variable speed,
Two modes -one for aggressive material removal -one for fine sanding,
The dust collection is so good that my wife has let me use the sander in our living room.