Futhermore, using Blake512 scrypt is just giving unfair advantages to people that already secretly ported the Yacoin's hashing algo into opencl, they will mine your coin far more efficiently than others.
all being said, unless you want to create gimmicky coin that end up nowhere like yacoin.
If I use LTC, then it will be easier for existing mining operations to adopt the coin.
The downside is there is no stickiness, no lock-in. Miners can always switch to yet another coin.
So there's got to be some way to have stickiness.... someway to encourage miners to stay around and mine.