I have two DVRs and know two other turners who also own them, and none of us have had any problem, apart from a mains filter which went 'pop' on one of them. Cost of repair was £25 including postage from Record Power who were Teknatool agents at the time.
Very smooth drive as there isn't any pulley/drive belt. And the fact that there is feedback to maintain the speed no matter how heavy the cut ( up to a point) means you aren't having to worry about belt slippage. Reverse is easily engaged but the lathe warns you when reverse is selected. Another nice feature is that, following a power cut it defaults to a speed of 500RPM, as there is no rotary switch to leave at max speed.
Regarding cost of repairs, the cost of an equivalent inverter or 2.5Hp motor is not going to be cheap either.
I guess it all depends on what price you are thinking of paying. I got both mine second hand at prices better than other lathes of similar capacity.