I've heard from people who have had sky their iptv went to shite with them -not sure how accurate this is but. If switching over from eir to sky you don't have to tell eir you're cancelling once sky process the switch correctly. A UAN on your bill is what sky need to switch over your service, depending on what service you have you may have 2 UAN on your bill. For peace of mind, always cancel your DD once the broadband switches.
got the sky modem this morning, much better speeds than eir and iptv seems to be working fine. cant go wrong for 30e a month.