I'm not real familiar with the iOptron stuff... but one thing if for sure - Synta / Skywatcher have sold THOUSANDS of EQ6 / NEQ6 Pro varients of this mount, they've been building them for years. I had one and loved it, superb value for money.
Re pointing accurancy - with precise GPS coordinates, time zone, good polar alignment through the suppolied polar scope and a simple three star alignment - pointing accuracy always put objects within the field of view of my refractor and Nikon D40 chip.
Do some image searches with variations of 'EQ6', 'NEQ6' and 'EQ6 Pro' within the Deep Space section of this site, google images and Flickr... results speak for themselves
They also come with a 5 year warranty...
Good luck, Logie.