Doing Time

I'm not familiar with the St Mary's books (you don't have to be but I suspect it would help) so o came to this with no expectations.
I enjoyed it but was often frustrated by aspects such as its length (there's a lot of editing potential here) and the sudden change in plot direction that wasn't particularly well foreshadowed.
There's a lot of confusion here - characters are referred to by their forename and surname interchangeably which meant I missed a few important details, particularly if the author assumed you'd read previous books.
The author's use of imperial measurements is also irritating. We've been metric for 50 years - is the suggestion that the UK reverts to feet and inches in the future?
There's also a significant plot hole in that time travel is ignored at important points. For example, why do the time police arrive after the crime has been committed instead of before it? Wouldn't that be more useful?
At times I felt I was reading substandard Douglas Adams or Terry Pratchett. That said, overall it was enjoyable and I'm tempted to read the next books or delve in to St Mary's.