After quickly perusing the manual, a couple of things stick out:
The 552 will not automatically switch between external and internal power, so you have to monitor your battery condition a little more closely than you do with the 7xx boxes. Perhaps this is SOP for the SD mixers, but I've never used them so it's news to me.
There is no display for recording or setup. Setup is achieved with the help of Synthetic Voice for Enhanced Navigation, or SVEN. Ya sure, a little Upper Midwest humor there, don't ya know. I wonder if SVEN sounds like a Norski. Too bad there is not an LENA option.
So how 'bout a little joke, then? "Ole and Lena got married. On their honeymoon trip they were nearing Minneapolis when Ole put his hand on Lena's knee. Giggling, Lena Said, "Ole, you can go farther if ya vant to"... so Ole drove to Duluth."