Considering how lazy these ports are, I'm not sure there's any reason to buy this collection instead of just emulating it all.
I bought the collection on the Nintendo Switch, through Amazon JP as a digital code (at a lesser price), for the personal convenience factor. Technically it's the first time I play the MGS games too despite watching friends playing them beforehand, so the Switch version was an excuse to get into these titles finally.
I dunno if "lazy" is the correct word considering Konami went out to include nice things like the fake PS1 memory card feature for MGS1 (which differs between MGS Original and Integral btw) but the Collection as a whole package was sure handled weirdly.
For example, the English versions had to be actually downloaded in-game, something that was not explicitly detailed (the international DLCs were also hidden from view on the eshop page by default), thus considerably increasing the initial filesize of the three games:
MGS1 : 4GB -> 5.7GB
MGS2 : 9 GB -> 12.3GB
MGS3 : 10 GB -> 17.8GB
I initially assumed the default filesize was from having the US and JP versions in-built at the very least.
This is again due of obtaining the Collection from Japan, the average Joe here won't meet that kind of problem in reverse unless curious enough to play the JP versions.
Another disappointing thing is that the savedata is not compatible between the JP and European/American versions within the collection, so progress cannot be shared between each other. By comparison, all three games in the Super Mario 3D Collection on Switch shared the same savedata regardless I would change the language at some point or another. A friend of mine was looking forward to play the MGS games with Japanese voices + English subtitles (for the novelty) in the Collection but was sad when he realized it wasn't possible.
As an anecdote, Japanese user reviews were heavily criticizing the poor packaging of the Switch physical since all it contains are Metal Gear 1 + 2 and MGS1 (with the rest as download codes), despite a 32GB cartridge could have easily regrouped all of the games. I recall the Playstation Vita cartridge had MGS 2 & 3 altogether and Vita physicals were a lot more limited in storage size back then (4GB max).