I had an EXII and they are very good machines.
There are so many coils to choose from that are much better than the stock coil. So far I have had the old white stocker, the black stock, the 8" Minelab, the Pro coil, the SEF 10 x 12 and the 8 x 6, the 6" excellerator and the 5" Sunray.
Out of all those I will suggest that an EXII should have the Pro coil on it if only one coil was to be used. The Pro coil is very Lightweight, just an all around great coil.
The SEF's are also very good but ounce for ounce I say the Pro coil is no. 1.
Just my .02 cents
Jeff