The one issue is a conflict between its stated aims, the first of which is -
"promotes the maximum public interest and benefit from the recovery, recording and research of portable antiquities;"
I am very interested in local history, its what got me into metal detecting and I have also written a little book about the men from the village killed in WWI.
To get the
maximum benefit (the first stated aim of the scheme) from local finds I need to know where they were found, as a cluster could indicate a unrecorded building / settlement, or if they were in a linear pattern they could well indicate an old track / footpath. IF finds are only recorded to the corner of the nearest 1K square then the building / settlement has moved, and the linear route has not only moved but become a single spot rather than a route. So as from the view of researching local history I need the exact location. The find becomes even more meaningless if only a parish or county is given.
However, from the view of a landowner or detectorist the last thing they would want is to have the exact loction of a cluster of given as they might as well put up a big neon sign saying "Nighthawks this way".
The other main issue I hear from detectorists is the time it takes to get anything recorded, should we really be talking several months before the finder and landowner gets a fairly routine find back?. I fully understand a longer delay for "treasure" or rare finds, but not for the more routine finds. Sadly I have also heard of a few cases where finds have "gone missing" once handed in for the reporting process (not with my FLO).
Another issue is the way some items are inaccurately recorded (eg the "Roman to post-medieval" mentioned above), where due to many years of experiece the detectorist can give more accurate information than a newly qualified and inexperienced FLO, this certainly puts some of the "old hands" off.
In my own case the main reason for infrequently recording finds is that I rarely make any

However, I have handed items to the FLO at club meetings that I thought he would record and he has commented on them and handed them back with out recording.
IMHO the whole system needs a major overhaul, and probably more money invested in it to get it to a "fit for purpose" state.
Evan