The interview itself was okay - there were standard competency-based questions and a task to prioritise a short to-do list, which was different and quite interesting. The interviewers were polite, although one was rather reserved and not very warm, which obviously doesn't help you to feel comfortable.
My main issue was that at the end of the interview they said they would be making a decision and letting the agency know the next day, but it wasn't until almost a week later that I heard anything. The quick turnaround they promised would've been great, but fine if they missed it by a day, but to leave it that long and over a weekend feels quite rude, especially as getting the interview arranged in the first place had been delayed as well (although that was due to sickness, so fair enough). It feels disrespectful of the time I took to meet with them, particularly as once the answer did come, they hadn't even given any personal feedback.