Gate Keepers is a wonderful anime from the year 2000. I often think back to what a great time I had watching it, not to mention how much of a bop the OP is plus the ED is nice too. I remember seeing them on Rightstuf's clearance list and it looked super interesting and the series turned out to be probably my favorite blind purchase ever. I can't really think of anything else I bought on a whim that really stuck to me.  I have compiled the JPN DVDs with English subtitles and audio from the USA DVDs. I did the episodes like, way back in February but just finally decided to finish the extras. At first I got the DVD-BOX but it didn't include the non-credit OP and ED or CMs so I ended up getting the original volumes. I discovered both the original volumes and BOX are the same encode however to simplify adding the English tracks, I used the volumes for 01-23 and BOX for 24 since they had the same structure as the USA version. First half of the show has 192kbps AC-3 meanwhile the second half has 448kbps AC-3. The USA version is pretty inconsistent with each volume having either 192kbps or 224kbps AC-3 and even has film frame-rate pull-down on the final volume. I also included the 224 Japanese audio just in case. The Japan release actually has some of the beginning of the episode 22 avant trimmed down meanwhile the USA version has full fade-in and audio for it. My primitive MKVToolnix splitting was actually surprisingly able to cut the difference correctly. I also learned that the full image is cropped. The horizontal framing between the JPN and USA versions are the same but the USA version is vertically shifted down. USA VOL.4 included the OP with original Japanese Credits and it doesn't have the overscan borders so there's actually a decent amount more to the image. One final thing to note about the JP DVD is that it is clearly a digital master (besides maybe episode 03) unlike the USA DVDs. That being said, I don't dislike the colors on the USA version but some lines/details end up getting "etched" which seems to be a natural byproduct of the tape scan. Just in case you're not familiar, a good modern example is Archives of Evangelion (mostly prominent in Death(TRUE)+Rebirth, perhaps they filtered the TV series since it looks mostly smoothed over with some small traces intact) since those broadcast versions are an 8mm tape scan and they exhibit the exact same type of artifacts. Below I put together a cheap comparison of the NCOP:  I also threw on the subtitles for the extras. Special Version EDs include VOL.1 translation only track and Romaji + Translation track from VOL.8 since they improved the timing over the previous volumes. I also made sure to include the English audio for the Special Version avant. The bonus DVD-ROM content is pretty cool and has a ton of extra information with images and high quality wallpapers including screenshots and some illustrations that were used for some of the CD releases. At one point I was also going to try and get the France DVDs to see if the cropping was any different and also to potentially include French language options but I didn't want to risk them getting ruined or lost in the post. If someone knows how to tackle correctly encoding these, that'd be super cool! I'm also hoping one day Discotek will pick up this series and give it their high quality Blu-ray treatment. As for Gate Keepers 21, I've had the USA DVDs since pretty close to the beginning of my anime life and I got the JPN DVDs last March and still haven't opened them yet (LMAO). I briefly checked out the WEB version and the only thing that might be salvageable is the EAC-3 audio except that it's only the 2.0 and not the 5.1 but those would be irrelevant if it ever gets the BD treatment. I'll get to checking those out soon now that I finally finished what I wanted to do with the TV series but 21 is kind of a turd so it's been kinda difficult to motivate myself to check those out. The TV series on the other hand is ultra good and I love it!