Blue tit again

[alxxx]

I have been trying to get a crisp shot of birds whit my 70-300 lens and have not been having much luck, well today i went back to jessops and asked them to check it for me, the assistant told me it was hunting a bit and that it shouldn't do that, so they replaced it and heres my first quick try,
do you think it's any sharper ?

this is from the old lens

 

[mmcp42]

might be easier to compare if you cropped and enlarged them both
(by the same amount of course!)

 

[alxxx]

done sort of