Got a chance to get out today and test drive the 10x12. Went to one of the worked out camps on my list. The deepest was a .54 3 ringer at 10" and most of the signals were iffy at best. The coil pinpoints well at the top section in the center. I think it will do better with time, but I think the stock 8x9 is the same as far as depth goes in our mild ground here. I would not use the 10x12 in a trashy spot thou, great for more ground coverage.
