That's really hard to believe. Even SGS2 opened apps faster than iPhone 4S. Both SGS2 and SGS3 have faster CPUs and more RAM than iPhone 4S and this is what matters most as far as he speed of loading apps is concerned. I have not seen a single review claiming that S3 was slow to open apps.
What do you mean that refresh rate was slow? Like it was blinking or something? Again, highly unlikely. Granted if you use live wallpaper and have a few active widgets this may cause some hiccups but you can easily fix it -just switch to "iPhone mode" (i.e. get rid of live wallpaper and some widgets).
There is more than brightness to how well the screen performs outdoors. Contrast and reflections are important. In fact, GSMArena concluded that SGSIII has the best screen for outdoor use:
Another area where the screens differ is sunlight legibility - the HTC One X is very good for an LCD and the excellent brightness contributes to that, but the non-reflectivity of the AMOLED screen gives the Samsung Galaxy S III the edge. In fact, the Galaxy S III emerges from our tests as the best outdoor performer we have seen to date.
Opening apps is also dependent on the read speed of the medium it's on. Maybe he's opening apps on a slow memory card?
In any case, it's already been widely discussed how the Android dalvik java VM system can handicap even the fastest CPUs, resulting in iOS having superior performance. It wouldn't be the first time it's been reported that the iPhone 4S outperforms supposedly more powerful Android phones