virtually every car on the road today is DBW and the reliability factor is a non issue. for the last 10 years most SXS's are DBW and you never hear of issues there.Until it doesn't work.
I watched a buddy do 3mph back to camp from Swingset cause his setup quit.
I will stick with mechanical.
in almost all cases when people have DBW issues, its because they used a cheap non OEM throttle, or crap wiring. Neither of which is the fault of a DBW system.