Mechanically they seem to be reliable, you hear a few things going wrong, but nothing serious that any model/make could have. Then there is what you plan on using it for, if it's a work ute/family truck with the occasional beach driving or camping trip, then it will do a good job. If you plan on doing more serious offroad work then they do struggle a bit. (mainly ground clearance, turning circle, wheel base and gear ratio's).
I would spend the extra and get the 140kW Spain STX over the ST. The Thailand built Navara's aren't put together as well. IMO.
Hope that helps.