Tamron or Pany Zoom for a55? Or?

There will be differences of opinion, of course, but is there a consensus on which long zoom (of reasonable weight) is the best all around performer on the a55?

My search of reviews shows about equal results in sharpness, color, etc for the Sony 18-250 and the Tamron 18-270pzd. I'd buy the Tamron in a minute if it had the in lens IS but since it doesn't, I'm sort of leaning toward Sony. I really don't want anything heavier. I'll use this lens primarily at Little League games and trips to Yellowstone.

Thanks for any input.