When comparing Edelrid Mega Jul vs Petzl GriGri+, the Slant community recommends Petzl GriGri+ for most people. In the question“What are the best belay devices for rock climbing?” Petzl GriGri+ is ranked 9th while Edelrid Mega Jul is ranked 12th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Auto-locks even if brake end of rope is not held
In case belayer is disabled, etc.
Pro Lightweight
Pro Passive assisted braking
Pro Three rappelling modes
Can be used in 2 orientations, for rappelling with or without brake assist, and can add a carabiner for lever action, making it similar to a GriGri.
Pro Anti-panic handle
Pro Active assisted braking
Pro Auto-locks even if brake line is not held
In case belayer is disabled, etc.
Pro Switchable between top rope and lead mode
Pro Wide range of rope diameters
(8.5mm- 11mm)
Pro Guide mode / Belay off anchor
Cons
Con Behavior is highly dependent on rope diameter and type
"stiff ropes feed very poorly. 9.7 and above ropes feed poorly for lead belay. Soft and supple skinny ropes don't lock as abruptly. Half ropes in the 8-8.5 range DO NOT LOCK FULLY with the proper edelrid strike biner" https://www.reddit.com/r/climbing/comments/6aoipn/nonjerky_method_for_rapping_with_mega_jul_in/dhh1vvx/
Con Guide mode with thin ropes can flip and disable auto-blocking
Video demonstration with stories of it happening in the comments: https://www.youtube.com/watch?v=385cP_FYNEs