I recently purchased a new string. The specs are the same as the old one however when I opened the package I noticed the loops had serving around them. The other strings I have seen in the past were just twisted through the loops. Any pros or cons to this type of string? It seems nicer to have the string this way but I don't know. My bow is fast flight rated and this is a d97 string.
Kinda sounds like you just got an endless loop string and previously used Flemish strings.
If the string length is correct for the bow either style will work fine. Some archers prefer one over the other for a variety of reasons/thoughts/opinions.
Guy