Critics and fans generally find it clunky. It uses repeated "stock footage" to pad the runtime and includes rough deleted scenes where the Fremen's eyes are not blue because the post-production effects were never finished.
It is roughly 177 minutes long and adds nearly 40 minutes of footage. It features a new 10-minute prologue narrated by a male voice over still paintings, replacing Princess Irulan's original intro. Dune - Extended(1984)H265.mp4
The "Spicediver" Fan Edit (Dune: The Alternative Edition Redux) Critics and fans generally find it clunky
This version was prepared for television in 1988 without Lynch’s involvement, leading him to remove his name from the credits. Dune - Extended(1984)H265.mp4
Most viewers consider this an interesting curiosity but a "painful experience" that over-explains the plot.