Just finished watching all of gantz in one day, also I've been reading like 300 chapters in the past 3 weeks, it's pretty much power rangers for adults.
yeah I used to read gantz up until I got caught up during the nyaryaon or w/e arc and then stopped when onemanga shut down (RIP) recently caught up to where the story is at now and boy it certainly changes
I didn't really enjoy much of gantz because nothing really made sense and the art was sort of strange at times and the characters all died always and some were just american celebrities who were there just to get naked... made it hard to get into some of the characters.
but I've kind of liked the recent stuff, sure it's just as stupid and unexplainable, but it's kind of cool seeing another human-like civilization interaction with ours. even in the context of an OVER 9000 and GRIMDARK sort of tale like Gantz is..