Well, some people either can't be bothered to learn their machine, or there's something wrong with their detector & they should be calling Garrett's excellent customer service reps to get it repaired. I have an AT Pro & an AT Gold, and the pinpointing is dead on.
When I'm working in the woods, ghost towns, or fields, I pinpoint 'off the tip' (find the left/right center, then pull back until the signal starts dropping off). If I'm somewhere like a well-manicured park, I use the 'x marks the spot' technique to be extra certain that I'm centered over the target and dig a small flap (or pop it if it's near the surface).
I will say that the 5x8 coil is amazing, both in terms of pinpointing and it's ability to sniff out good targets in trashy areas. I suspect that you would really like it for parks & tot lots, though the 8.5x11 is also excellent.
Hope this helps!
William in Sunny SW New Mexico
Garrett AT Gold & AT Pro, Garrett Pro-Pointers, Lesche & Fiskar's Diggers, Garmin Oregon 450 GPS, ASUS Tablet (Great Topos!)
To paraphrase Thomas Jefferson: I believe in luck, and the more I dig, the luckier I get.
note to self: It's only a hobby, It's only a hobby, It's only a ....