Hi Victor,
My two cents worth.
I've owned the Bartech Digi/Heden (Ver 1) and RT Motion Mk2.
If cost is a factor, and it is a choice between the Bartech and RT Motion. I'd go for the Bartech.
However, with the M-One motor on going service issue and not many makers of analog motors nowadays. I would bite the bullet and buy a Bartech Digi (Ver 2). You get auto and manual calibrate and have 16 bit resolution compared to 12 bit for the analog) or HocusFocus Axis1.
I personally went for the HoFo Axis1 mainly for the speed and ability to do really slow racks, auto and manual calibration, auto lens torque detection, the motor will freeze if it detects something jammed up between the motor gear and lens, so that you don't end up accidentally grinding or damaging your cables or fingers.
You can buy a RedRock Micro Torque motor ($500) or soon to be released Red Technica Element Motor ($1200 ?) as a spare if anything should happen with either systems.