Vapodog,
I hear you. I bought a second hand Sako forester .308 with a Tasco 3x9 on it. I shot it for the first couple range trips with the Tasco. Then, when I decided I wanted to keep the rifle I put a Leupold on it.
The Tasco did not give any trouble, it performed fine.
It was just that I did not feel comfortable and had no confidence in it.
May be the Tasco would have given me a lifetime of service, may be not.
We have to do what we are confident and comfortable with.