I assume you mean Warp Stabilize, which is entirely different than stabilize. Warp Stabilize a 28 minute video is --- well, nuts. A single 28 minute hand held shot? If the 28 minutes is not one continuous shot you cannot use any kind of stabilization. You cannot stabilize across cuts. It can't be done.
Cut up the shot into manageable segments by finding cut points and stabilize a minute or two at a time. You are trying to cram 28 minutes of video into ram at full rez then perform calculations on it. I know of no tracking software that would be up to that task.
Thanks. You know, I figured as much, which is why I had just started it again with just a bit more than 50% of the entire file. I'll be back in a few to let you know how it worked. "A minute or two at a time?" On an older windows laptop (dual core), I was able to do 8 minutes. Shouldn't this bada$$ iMac be able to do more?