SX60 IS.....?

I've bought and returned two SX60's now, and am still trying to figure out why the results I got with it were consistently poorer than those I've been getting with the SX50. I really wanted to like this camera since I shoot mostly birds. The extra reach and better viewfinder are very appealing, and I was prepared to accept a small decrease in IQ and some increased noise in return for these features. However, I wasn't expecting to have to work so hard just to hold the image still enough to get the camera to focus....or, in many cases, NOT focus.

I've never had to use the Frame Assist Lock on the SX50, even when shooting at 100x digital without telephoto. As a matter of fact, I've found that using it can be counterproductive, perhaps by causing me to move the camera slightly while deploying it. Contrarily, the movement seen through the SX60's viewfinder (even with IS set to "Continuous") was so extreme, it dictated the use of this button on virtually all shots. Without it, it was often impossible to keep the focus square on the subject long enough for the camera to find focus. The catch 22 is that one is supposed to get a focus lock before pressing the FA Lock, and doing the reverse results in 4 or 5 seconds of IS chaos before the two synchronize....a delay that often results in missed shots when one's subject is wildlife.

I'm hoping others who are using/ have used the SX60 will let me know whether or not they've had the same issue. Maybe I was just unlucky enough to get two cameras with defective IS systems?