That is a tough call for me, since I feel each has its place. Having said that, considering the type of hunting you will mainly be doing, I would go with the stock 10" concentric. The 11" might be an inch deeper and of course, does separate targets a bit better in heavy trash, and will cover more ground, but it also likes bottle caps, which are usually quite prevalent in most parks. With the 10" it can get much closer to fences, play ground equipment, in and around bushes and for long days afield, in is a nice light weight swing. And, it will surprise you with its target separation. My 2 cents, anyway. You made a good detector choice, i m h o. HH jim tn