Here is Apple's appeal.

http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX...

> They both depend on the arbitrariness and non-generality of a company-specific tax ruling.

Thats an opinion not a fact. The case has yet to begin in court.

IMO Apple did not get any special treatment. Basically all you need is a country like Ireland where an onshore incorporated become non-resident if controlled offshore [1]. And Ireland must be not be considered as tax haven [2] by USA [3] otherwise Apple Sales International would be taxed as per USA laws whether Apple USA repatriates or not.

[1] This was true until 2015.

[2] IIRC Ireland must be considered tax-fair country. Obviously a more strict condition.

[3] Now here Ireland enjoy the benefit of single USA-EU tax treaty.