The older Saturn units with led use JVC cd-drives.
The slim lines use Sanyo drives.
Japan mod can be done,look for jumpers JP6,7,10,11.
2 have traces that need to be done away with,and two other need to be linked together if you want to make a straight accros import playing system. This would come in handy if you want to play KOF 95,Ultraman,Fighters History ect.
The other ram cart titles can be used with the normal 4n1 carts that have all region play.
If you desire also,you can do the above mod with a toggle switch.
Depending on the saturn revision,the jumpers will be in different areas,either on bottom or top of the motherboard pcb.There are a few revisions,so you would have to look around.
The Sanyo drives are not as dependible as the JVC drives.
At this rate though its kinda moot discussion unless your taking a first generation deck and a second gen deck new right out of the box.
Used decks will have a varied life span depending on the abuse and use placed on them.
If you have a s-video tv Id get a s-video cable.Works great for almost all games,except maybe Drac X,because of some mode it runs in,you get a ugly picture near the top of the screen in s-video.The picture is still sharp however.
The Saturn supported HD in hardware,but Sega never begin to push it as a feature. Its one of the few systems I know of that used so many video modes,low res and high,in hardware back and forth.Fighters Megamix was a good example of this,as depending on what stage you were on,it ran in either low or high res. Finding a HD cable seems to be impossible though. Ive yet to come across one,and back in 99 I tried to haggle a Sega repair tech over it,but to no avail. 1-800-USA Sega was useless.