If you have the means, buy the game on a Steam sale (often $9.99) to support Rebellion. You get a hassle-free experience with achievements and online play. However, if you are an offline archivist, a player with no internet access, or a enthusiast wanting to benchmark the remaster without paying, the CODEX release remains a gold standard of cracking.
The remaster refines the ballistics. Unlike standard shooters where your crosshair dictates the hit, Sniper Elite forces you to account for: Sniper Elite V2 Remastered-CODEX