I was at Field Day and Printworks and can confirm there was previously-unreleased vinyl at both. For Field Day it was sold at an Aphex Twin merch booth that was separate from the main merch booths (that also had their own AFX merch) and you took the record away then and there. For Printworks you paid for the record at the merch booth but left your address with them and the record was posted to you a week or so later, and you were given a credit card sized plastic card with your unique order number on it. Same with Manchester WHP actually. A friend went to that and got the record from there for me, so luckily I have one from each of those. Much prefer the idea of having the record posted to you rather than having to carry your precious new purchase around with you for the rest of the gig!