@chakster, I do not know why I am wasting my time with you, (your rudeness does not really warrant a response), but I guess the internet is full of misinformation and we do not need more... Before any of the models you mention were around, the XV15 and Stanton 681 were an industry reference. Stanton 681eee MkII for instance had a stereohedron tip https://www.vinylengine.com/cartridge_database.php?m=any&mod=681eee&t=any&sort=2&Search=Search&sty=&ovlo=&ovhi=&can=&dclo=&dchi=&stid=&masslo=&masshi=¬es=&prlo=&prhi=
The last iteration, the mkIII was elliptical. At that time, I believe that the 881 had replaced the 681 as the reference in the Stanton lineup.
The 681eee was hand-selected and carefully matched by Stanton. it was an upgrade from the otherwise similar 680 body. The XV15 was also similar (Pickering was a sister company) but had different styli. the XV15 625, 750, 1200 ( I believe there was also a 1800) were all top of the line at a given time. These are interchangeable between the 680s and the XV15, with the caveat that at some point Stanton and Pickering implemented a change in the angle of the bodies. This will result in the wrong VTA if one does not have the correct stylus. These are great sounding cartridges. Is there better? Yes, there always is...
The fact that these cartridges became linked to DJs for obvious marketing reasons late in the history of these glorious companies does not change the above statements.You are welcome to believe what you want to believe about the sound of these cartridges, I could care less. If you indeed think they are trash, please send me all your records that have been mastered with a 681... I will happily relieve you of that burden. The OP already has the cartridge. It is worth a try IMHO. He or she could easily make up his/her own mind. My answer to the original post is that it will take real money to better this cartridge if it has a top stylus (even the elliptical 625 is quite good).