Designed to aggressively compete on price and performance with the Griffin AmpliFi and XtremeMac Tango X2, Grace Digital's new GDI-iDOCK5 ($150) is an all-in-one 2.1-channel audio system with a 5.25" subwoofer inside a stylish, large cabinet. With flecked black coating that looks like granite, and measuring 16" by 10.5" by 5.5", the GDI-iDOCK5 is bigger than its peer systems, equipped with a metallic front dial, and the only one to include an integrated…