Shackleton is on the outskirts of Lucan but so is Rokeby Park and, to a lesser extent, Laraghcon. Traffic from Rokeby and Laraghcon is quite bad as well. None of these 3 estates appeal to me for these reasons.
Distances to shops / village are similar:
I've no particular love for Laraghcon- nor apparently do the many people who have sold there in the last 24 months (see propertypriceregister.ie for the bewildering number of sales up there)- but I also don't have any love whatsoever for Hawkridge or the other 'luxury gated communities' of Lucan.
Shackleton Park is trying to skirt on the coattails of the likes of Hawkridge/Laraghcon/Rokeby- with a Ryanair'esque understanding of 'outskirts of Lucan'.
Saying somewhere a 2.6km walk away is 'on the outskirts of the village' is telling a porkie pie in my mind.
As for bad traffic- I live on main street in the village. Its far from unusual for it to take >20 minutes to get from the Garda Baracks to Ulster Bank (I'm in one of the townhouses there). At least Laraghcon/Rokeby get priority into the village (by virtue of the traffic lights being managed by Fingal Co. Co, and not South Dublin Co. Co.- the bridge over the river liffey being the border between the two local authorities.