OK, looking good so far... rooted, most of the crap removed, 45k in antutu and standing in the driveway GPS Status is getting a fix in a couple of seconds, 9/10 sats and accuracy of 2-16m (average about 6), for comparison my Xperia T takes about 4 seconds for a fix, 11/21 sats and accuracy of 3-12m (average 4-6). Haven't tried to nav anywhere yet though...
My T already seems comically small, haha.
Now just to hope for some CM loving.
Downsides so far... the main buttons don't light up (come on!) and I'd much rather a 'recents' button than a settings one, although long-press on the home button brings up the recent apps list.