I'm not sure if it was overrated or not but this is my two cents on the system:
5. CONSOLE AFFORDABILITY:
Although N64 cartridges were more expensive than PS1 discs, Nintendo made up for this in the affordability of the console itself. As CD-ROM technology was still fairly new in 1995 when the PS1 and SAT came out, they started out at $300-$400. Whereas the Nintendo 64 at launch was a mere $200 (plus $50-$60 for Mario 64). So while the games may have been a bit pricier, the console itself was much more affordable.
4. NO LOAD TIMES:
Being the first ever major consoles that needed memory cards (though the Saturn could use a main battery) and the relative slowness of the CD-ROM drives, the PS1 and SAT were plagued by loading times which really slowed down the gaming experience. Nintendo knew this and was all the more reason they chose to stick with cartridges for faster smoother and (mostly) load time-free gaming.
3. ALMOST NO NEED FOR MEMORY CARDS OR OTHER ACCESSORIES:
While memory cards are pretty much mandatory on the PS1, most of the blue chip Nintendo 64 games save right on the cartridge and either don't need memory cards at all or make them optional (for example, Mario Kart 64 saves the major stuff like cups and time trial times on the cartridge but you need a memory card for racing ghosts). Not to mention the fact the games save much faster than they do on a memory card based format. Furthermore, most of the Nintendo 64 games (except for Ocarina of Time, F-Zero-X and Super Smash Bros to name a few) don't even use battery backup, so there's no need to worry about the battery dying either. Furthermore, the N64 was the only console with standard four controller support in the Fifth Generation (and so was the GCN in the Sixth Generation); four player support needs an optional accessory on the PS1.
2. DURABLY:
Unlike disc based consoles where the discs must be carefully handled by the edges and kept in their cases (if you don't want them to be scratched all over), cartridges are much more sturdy and if some careless younger gamer just leaves them strung around all over the floor, that's not nearly as big of a deal as if they were discs. Like it or not folks, younger gamers were and are a key part of Nintendo's target demographic and know that they sometimes don't take as good care of games as more experienced, older gamers do. Furthermore, because of the lack of moving parts, Nintendo 64's (and most other cartridge based consoles) are very much built like Tonka trucks, built to last, while the PS1 (and PS2, and PS3...) can get DRE'd just from being bumped the wrong way.
1. COLLECTIBLITY:
Of course, Nintendo wasn't even thinking about it at the time, but now that it's been ten years since the end of the Nintendo 64 era, many classic gamers (such as myself) have taken a liking to and are now collecting Nintendo 64 cartridges. For any disc based console, you pretty much have to still have the original cases (or put them in your own jewel cases), but for cartridges, you can just do cartridge only (and go online to read most of the manuals) and just have them in a shelf no problem!
