I replaced my 100-400 with a 70-300 and LOVE it. As good optically (or close enough you won't see a difference in prints), $500, and SMALL!!!
I have a question though. Anyway to get the AF-ON rear button to shut off the image replay? I'm used to hitting that to kick the camera out of replay... The way it is now it'll pop up the replay with my face to the camera, I'll try to use the stick to move the AF point (just after using the rear AF button) but it's changing the replay info or pic.
I've found 2 walkarounds, but they're PITAs. The first is to relearn to tap the shutter halfway which works but isn't how I'm used to doing it (15 years with canons is hard to retrain overnight). The second is to turn off the replay (what I'm currently doing) as I only chimp ~25% of my shots anyway, but then when I WANT a replay I always find myself blankly staring at the back screen with nothing on it thinking it'll pop up.... Also something I need to retrain, but seriously why wouldn't the AF button kick the replay out? Nikon can't really defend that to me in any way that makes sense. You want AF, you don't want replay, you want replay, you don't want AF, it should be a simple as that, no?