While Patch 1.14d was primarily a maintenance update, it addressed several long-standing issues that affected the multiplayer experience:
While 1.14d was primarily a technical patch, several quality-of-life changes were implemented that affected gameplay loops. diablo 2 patch 1.14d
For those returning to the classic client, updating is straightforward: How To Update Diablo 2 to Newest Version V.1.14D ~ EASY While Patch 1