D97 is my preferred string,I find it quieter then 8125 and it cost less.I believe they are the same material,just D97 is slightly larger diameter.And here in the states D97 is alot less costly.And D97 you can get in 375 ft rolls and 1/8# and 1/4# spools.Here a 1/4# spool of 8125 cost about $12-$15 more then a 1/4# spool of D97.A 12 strand of D97 is strong enough for upto a 100# bow,I use .024 halo serving to give me the same nock fit for all my bows from 50# to 83#.Just a combo that works for me.I still like to pad my loops,I think that hleps to make the string quieter.