I have the original 200 watt ETS 125, the 250 watt Pro 5 (just an updated ETS 125), the cordless ETSC 125 and the brushless 400 watt ETS EC 125.
The best one in the bunch is the ETS EC by a long shot. With a 3 mm sanding stroke and being brushless with 400 watts of power means that this is a serious sander for many tasks.
The other 3 sanders all have a 2 mm stroke and so they are less aggressive. They're pretty much finish sanders and that's what they were designed for. [smile]
Of these 3 sanders my favorite is the ETSC cordless version.
My least liked version is the original 200 watt ETS. The extra 50 watts makes a substantial difference. The Pro 5 and the new ETS sanders are both 250 watt models.
I periodically swap between the 5" & the 6" pad on the ETS EC. Sometimes smaller is better. [smile] Purchasing larger diameter sandpaper is cheaper than purchasing another sander.
The ETS EC must be used with a vac as it has no internal blower to remove the dust.
The ETS, Pro 5 and ETSC can be used with a vac or the optional dust bag as they have an internal blower/fan.
If I could only keep one I'd choose the ETS EC...If I could only keep two I'd choose the ETS EC and the ETSC.