The stargate has it's clear pros, but also it's clear cons. It only works with 3DS consoles because of the form factor and the DS mode doesn't work if luma CFW is installed. Also, homebrew support is really bad because the DLDI driver doesn't work properly (can be related to exfat support).
But yeah, it's the only DS flashcart to support exfat so it's the only card where you can put all of the DS games onto one SD card and play them (without formating FAT32 devices to a larger size which windows doesn't support with it's utility).
the dldi thing in particular is a little bit of a shame, it might have been cool to have twilightmenu running on it natively and being able to select 3ds games through twilightmenu instead of wood. but for homebrew I'm not necessarily sure it's a big deal, because most up to date homebrew these days is built to run from sd card instead of slot 1, with twilightmenu, so the need to have a flashcard for running ds homebrew isn't there as much
meanwhile a slot 1 card is still relevant for running commercial ds games, until nds bootstrap becomes good enough to be able to run every single game from start to finish without any major issues (it's getting there, but I don't think it can ever be perfect because of hardware limitations on sd card reads and such. like for pokémon gen 5, they have to turn down sd card read speed by a lot to prevent wireless communications from desyncing, which makes the games unplayably laggy when wireless communications are in use, but if the game is running from slot 1 instead of sd, that problem doesn't exist)
if you intended on keeping the console unmodded, then yeah being able to run ds homebrew from the card is important. but imo it's not worth it to stay unmodded, if you get a card like this you should have cfw alongside it, and then ds homebrew you would run from twilightmenu instead. I guess some homebrew might need to be run from flashcart still though, like save editing apps that need to be able to access the save data for your ds games, so it would depend on how much you need those or not
what I'm wondering though, is speaking of cfw, if it's possible we could get unsigned .3ds roms working from either sky3ds or stargate, as long as you had cfw to disable cartridge checks and all that. so I tried, the twl menu for stargate doesnt function with decrypted roms but the roms appear to be functional within the menu and are selectable once you re-encrypt them. but then once you get back to the home menu, you find that the next rom was loaded instead (the buttons skip over the unsigned file, as well)
I'm guessing the card's firmware itself is doing the signature verifications by itself before letting the home menu see the rom, because there's no way the home menu could force stargate to switch to the next rom. unless there is no check on the firmware side, and it just reacts to the home menu rejecting the unsigned rom by automatically loading the next one instead. I would assume that cfw doesn't currently patch out cartridge checks for 3ds games, because why would it? there was never a need for that kind of patch.