Tamron 28-300 Canon Mount

hello.  What are your thoughts on the tamron 28-300 lens for a Full Frame Canon?  The use for this is strictly a lens to carry around for travel purposes.  I do own L lenses and realize the quality will not be as good but i would look for this lens to be the type if i went on a day trip and didnt want to carry a lot of glass.  The other option would be to use the 24-105l and carry a pocket zoom camera.  but for $600 is it that bad of a lens?