I've been through a few processes in the last year, and have an IAA CPL. I've yet to have any problem at-all, and find their communications excellent (the forms are pretty clearcut too I thought, if sometimes lengthy). If you have names of anybody, all their email addresses are
[email protected] .They do however seem to be primarily working from home, which is probably why the phone isn't much help.
Most people I know in the UK seem to be using Malta at the moment, second most popular Austria, third Ireland. I've not actually heard any significant complaints for any of them (not compared to our own dear CAA anyhow).
G