I am informed by Revenue that they understand that Irish SPVs is a reference to companies that have notified the Revenue Commissioners that they are qualifying companies for the purposes of section 110 of the Taxes Consolidation Act 1997 (section 110 TCA).
As of 31 October 2016, there are approximately 2,480 companies with live tax registrations who had supplied a notification to the Revenue Commissioners that they are a qualifying company for the purposes of section 110 TCA.
As the section 110 TCA regime was designed to provide tax neutrality, it can be assumed that the majority of companies using the regime achieve some measure of tax neutrality as far as corporation tax is concerned.