Is special redemption the Achilles' heel of Calvinism?

Of all the “five points of Calvinism” the one that bothers me most is Limited Atonement (or what many Calvinists prefer to call “Particular Atonement”). While I find unconditional election and irresistible grace troublesome and problematic, they rise nowhere near limited atonement in terms of departing from Scripture, tradition, reason and experience. 

http://www.patheos.com/blogs/rogereolson/2013/02/problems-with-calvinist-polemics-against-arminianism/

i) Olson judges limited atonement to be wanting according to the Wesleyan Quadrilateral. But even if that were true, why should the Wesleyan Quadrilateral furnish the standard of comparison?

ii) Since there is no consensus position on the scope of the atonement in historical theology, limited atonement doesn’t depart from tradition–even if that was relevant.

iii) In what sense does limited atonement depart from reason? Does Olson think the extent of the atonement is something we can know a priori, without reference to divine revelation? Does he have an ontological argument for unlimited atonement?

iv) In what sense does limited atonement depart from experience? We don’t directly experience the atonement. Like justification, the atonement is objective rather than subjective. Something God does for us, not in us. The atonement affects our judicial standing with God. A status, not a state. It doesn’t change us. Rather, it changes our relationship with God. At most, we experience certain consequences of the atonement.