~1.8 GB for 30+ episodes (compressed but watchable). Played smoothly in VLC and on my phone. No malware or weird watermarks – but always scan your downloads.
The arc's conclusion features some of the most heartbreaking moments in anime history, which are essential for Luffy's growth. Where to Watch in High Quality One Piece Marineford Arc Download 72018
It seems you're asking for a review of a download of the in 720p (likely a typo for 720p, not 72018). Below is a sample review written as if from an anime fan who downloaded a 720p version of the arc. One Piece Marineford Arc Download 72018
★★★★★ (5/5 for the arc itself) / ★★★★☆ (4/5 for this specific 720p download) One Piece Marineford Arc Download 72018