The L-500XL isn't the Dimebucker,but it is the original pickup he used.
I've never tried the Dimebucker I've always used the Xl.
IMO,buy the Xl and pocket the cash you saved.The XL's a better pickup on top of it. Check out billlawrence.com
As far as the 81 or the Xl go,all personal choice.Some quickly go 81 others go XL.
You should be very happy with either.