Colorado based manufacturer, Big Agnes, is largely renowned as a leader in terms of tents in particular. However, the popularity of this particular ultralight tent on the Pacific Crest Trail etc is testament to the functionality of the design.
At just 3 lbs 8 oz this is also an incredibly light tent which has more than enough space for two peoples. At the same time, most long distance hikers prefer to use this model as a one man tent, for the little extra space.
Aside from the MSR Hubba Hubba, there is no contender to Big Agnes for regarding an ultralight tent for the Wicklow Way, or any way for that matter.