Hi, the 150mm f/2 has a tendency to seduce me with the rave reviews and all the overwhelming evidence that it has absolutely amazing optics. However, my main use for long lenses is wildlife shooting and I'm not sure how useful 150 mm is for that. I'm afraid that it will be too short most of the time. I know it turns into a 300/4.0 with the EC-20, but my 500 f/4 turns into a 350/2.8 when I put on the speed booster so the only real benefit of the 150 with EC-20 would be autofocus. On the other hand, having a long F2 is probably a good thing, I have learned that I can never get enough reach or enough speed when using long lenses. Any thoughts?