This is the final year of IRD's move to their new system. It was not fully done when the system went live after their shut down (e.g student loans were still largely on the old system), there are a few things that apparently technically can't be done - but it's a vast improvement on the old system. The website has been updated, and there is even a list of what's been done since it went live, and what's planned to be done. They really are listening and trying.
Of course as everyone gets used to it there are usually significant delays calling IRD - but even this now shows on the website. And at least issues advised via secure e-mail are now answered in what seems like amazingly fast time.
Just a reminder - they will never email you directly. If you get an email from them asking for you to do anything - it's spam. When they do email you, you will receive an email saying simply they've sent you a message and login to MyIR to see it. I repeat - anything else is spam.
One thing that's important is to realise IRD has now entered the 21st century. Just as virtually all businesses operate their bank accounts on-line, so now all taxpayers should use a MyIR account. (You should also use a MyACC for business account.) It really does simplify communication with IRD, not to mention letting you see exactly what they've done with returns and payments.