I've owned this lens for a while now, & can thoroughly recommend it to any Sony alpha user. The quality of the pro range glass blows the kit lens I had before out of the water.
Having a built-in motor, a first for me, I couldn't believe how quiet this lens is. You'll hardly notice it focusing. It's quick too, & rarely hunts.
The only downside is the size. It must be at least twice the size of the 55-200mm kit lens I replaced with this. But for the quality & quiet focus, it's worth the extra bulk.
The oddest thing is, mine rattled out of the box. It sounded like maracas. I thought I'd got a duffer, & took it back to the shop. They had another, & that rattled too. I've spoken to other people who have or have tried this lens, & they noticed it as well, so it's obviously something to do with the design, & not a fault with my lens. So don't be phased if yours does. Even weirder, when fitted to the camera body the rattle stops.
All 'round then, an excellent, quality lens. Just as you'd expect from the Sony pro spec range. It's suitable for full frame too, if you own or plan to upgrade to one.
If you have a Sony camera, you have to have this lens. It's as simple as that.