Yes - we have had problems.
A new machine that had to go back to the States with a pcb fault - under warranty, but down-time was about a month. (RL Dolby provided us with a loaner)
Also, a problem with the entry point for the ECG cable with the proprietary trolley, which is so poorly designed it causes the cable to bend and fail in a shorter time. This has been rasied with RL Dolby also.
Thirdly, the internal (upper) case screw pillars cracked releasing broken parts into the unit. This requires a new upper case - JUST outside of the warranty period.
We are starting to loose confidence in this machine and the quality of manufacture. Come back MAC6 all is forgiven .. !