I've been using my Tamron's for sports with the K5. The 28-75 2.8 and the 70-200 2.8. I had a 55-300 but got rid of it. There was a time that I thought I needed more when in fact I needed less.
For as much as I love the 70-200, I've been using my 28-75 for an all arounder. Here are some panning shots I took this weekend with the 28-75
and some from the 70-200....more reach then I'll need
Edit:
Just saw the part that said "cheap"....I bought both lenses used. I think I paid about 300 for the 28-75 and about 625-700 for the 70-200. Both were worth every penny.