>>51085798IPS offers blatantly superior colour reproduction and viewing angles. The cons are that it costs more, doubly so for high refresh rate monitors although those are fairly new, and has marginally higher input lag. It is not a meme, although it may or may not be preferable in your use case.
g-sync is a proprietary implementation of adaptive sync made by nvidia that only works on nvidia hardware, they charge an arbitrary premium to monitor manufacturers to implement this. Although adaptive sync is a new and interesting technology g-sync is most definitely a meme and you should wait until nvidia gets their head out of their asses and supports freesync before buying an adaptive sync monitor if you own a nvidia gpu.
