AIB have had this account for over 6 months, but keep extending how long the high interest rate lasts for. 4% is the annual rate, and they offer the high rate for a few months.
It's probably more hassle than it's worth to open lots of current accounts. Some of the accounts require minimum lodgements each month, and some require a minimum number of transactions to avoid fees. Most also require you to take out an ATM card, which attracts government stamp duty.