I have been using the 8 inch ML coil on my original XS since 2001 and have always had great success with it.
It is especially good for us woods hunter in getting around all the obstacles. It pinpoints better than the stock coil in my opinion and with that if you want to reduce weight more, than the X-1 accessory is not quite as necessary.
Probably 75% of all my good finds with the XS since 2000 have been found while using the ML 8 inch.
However, if I find I am at a homestead where instead of finding most relics and coins in the 4-8 inch range which is normal, that they are 8+, I will always go back and search the same site with the stock coil for possible mop up finds that might be a little bit deeper.
I can say over the years there have been a few finds that I am sure the 8 inch would not have picked up, but that has been the exception.
For beach and open field hunting though, I think the stock coil is the wiser choice initially and then when you are in where perhaps a homestead or work area was in the field, come back with the 8 inch and very slowly hit the heavy iron area for those missed goodies.
I did compare my XS with the 8 inch coil against my son's Fisher's CZ70 and my old Garrett GTA1000 and Fisher Excel ID.
The 8 inch coil on my XS is equal to the Fisher with the stock CZ70 from all the comparisons we have done over the years.
The 8 inch coil on my XS is better in depth by a few inches against the Excel ID and GTA1000!
In other words, I like the 8 inch.
Don