I've listed the Flaws of Darkcoin and Monero.Darkcoin's Flaws:
1) Darkcoin has a 50% instamine by it's own developers during launch, as the block reward was set to 500, and there was no windows wallets/miners. Evan, the developer, and Internetape, the other developer, instamined over 1million Darkcoin's within 24 hours.
2) Darkcoin's name itself, Darkcoin, will always be affiliated with illegal activity like the Darkweb, Drugs, etc, and the name itself ensures that Darkcoin will never reach anything close to mainstream acceptance.
3) Darkcoin's "anonymity" is based on coinjoin, it simply mixes users coins around, making it harder to track it. However, if even the slightest taint if found when mixing the coins, an investigator will be able to deduce who sent what and who received what. The maker of coinjoin, Gmaxwell, deeply criticized Darkcoin since it's coinjoin based "anonymity" is basically a joke.
4) Darkcoin's mixing system/coinjoin relies on something called Masternodes, Masternodes are nodes that are set up by people, anyone can set one up, and Masternodes are the things that mix the coin around. Masternodes also present many risks besides giving trivial "anonymity", if all masternodes are owned by one individual, he will be able to "de-anonymize" Darkcoin and see all transactions clearly.
5) Darkcoin's Masternode Payment system has forked the network many times, and has failed Twice in the effort to pay the owners of Masternodes.
6) Darkcoin's Masternode/Darksend system is closed source, so that means the developers could be stealing coins, or doing any other malicious things, and it will remain unnoticed
7) The Masternodes can always be DDOSed, effectively shutting them down, if the majority of Masternodes were taken offline(they are mostly hosted on Amazon servers), then Darkcoin's trivial anonymity will completely shut off
There are
many many other flaws, it will take up too much space to list, so I've listed the main ones.
Monero's Flaws:1) Monero's bloating/scaling is an issue, where the blockchain itself takes up a lot of space on someone's computer, however, there have solutions to this, as shown by Crypto_Zoidberg, after he fixed this issue with his own coin. The issue has pretty much been fixed anyway, since bloating was caused by dust payments from pools, and with a recent update, those dust payments have been taken off. But because I think it will look to unfair compared to Darkcoin's 101 flaws, I had to list a "flaw" for Monero
2) That's it.