Just had a quick play, and only basing this on what I can see on the camera's lcd, but I am perfectly happy with the results, you may think they are under exposed though, and there is a good reason, PTTL exposes flash to not blow the highlights.
Let me give you an example:-
4 weeks ago I helped a friend shoot a wedding, he was shooting with a Canon 450D with a speedlight. Almost every single shot he took of the bride, using the flashgun, was heavily over exposed, dress blown out, didn't look good at all.
I was shooting with K20 / 16-50 and K10 / 60-250. Not one of my shots has a blown out dress, all detail on that dress stands out, but if you look at the whole picture you may say it was underexposed.
Difference is that it is easy to give a little boost, but if the highlights have gone, they're gone. Most people will agree that flash control is behind the competition, but when you know why it does what it does, it is actually extremely useful!
Besides, you can always just dial in +1 compensation and that should solve your problems for you!