Just done the VRT. That was hard. I got all of the practice ones correct, but definitely don't feel as confident about the actual test. Having different sets which only had 3 mins each sort of threw me off too, as some sets I could get through with lots of time left over, but then couldn't use that extra time for the subsequent sets which were more difficult.
For those asking about the practice test, yes you can log on and attempt it and it will just take you back to your dashboard afterwards (not straight into the actual test).