My first Festool sander should be....

[Bikeboy80]

I started with the RO90, because I had a number of small stripping and sanding projects to complete. Then I picked up the Ets125 which is an absolute dream to use. Then the slide continued, Ras115 then Rts400 then Ro150, each sander has it's own set of strengths. The Ro150 for me is my least used but when I need it to really level an area out it makes the 90 seem like a toy!

 

[Stephen B]

I started with the RO90, because I had a number of small stripping and sanding projects to complete. Then I picked up the Ets125 which is an absolute dream to use. Then the slide continued, Ras115 then Rts400 then Ro150, each sander has it's own set of strengths. The Ro150 for me is my least used but when I need it to really level an area out it makes the 90 seem like a toy!

Recently purchased RO 150 and am very happy. But ETS 125 and 150/3 are still being used, the 125 because of its size and lightness and the ETS150 for its very fine finish.

However if you only wanted one sander get the RO 125 or 150.

 

[leakyroof]

I started with the RO90, because I had a number of small stripping and sanding projects to complete. Then I picked up the Ets125 which is an absolute dream to use. Then the slide continued, Ras115 then Rts400 then Ro150, each sander has it's own set of strengths. The Ro150 for me is my least used but when I need it to really level an area out it makes the 90 seem like a toy!

too funny, and True!! "The Slide continued"

 

[Steamer]

I started with the  RO 150 and a dust extractor and never turned back. Really makes a difference in your work, productivity, and attitude.