I’m sort of a dilettante woodworker, but I’ll put in my two cents worth. I have a Rotex 125, and judging from the comments on FOG I should have bought a 150.
I have a DTS 400 and will probably sell it, as it always vibrates too much.
I have an RO90 and it is my most used sander; for remodel work, and drywall corners, etc.
I have the older ETS 125; it’s good for finishing; but I’m really tempted by the new brushless model, will give it a try at the local dealer. I don’t really need the cordless feature as the dust collection will always be needed.
Since I don’t need production speed, for the most part I’m fine with the 5 inch sanders, but the Rotex 150 for external siding prep sounds good.