Hi Martin
I have had a lot of experience with agency staff both skilled and unskilled, there is no surprises, some are good and some are bad and will need vetting just as you would if you had employed them yourself.
Was there anything in particular?
The up side is that there is at least someone to moan to on the end of a phone and you do get to source some good people with minimal risk ie paye.
Not sure about those costs though, ok if you can still get a return, but don’t expect too much as they will need just the same amount of supervision etc.
DP.