Considering that this template has not been updated since 3 August 2014 I am impressed that it still functions as well as it does.
The only glitches I have so far noticed are:
Slides in the Nivo Slider now appear on the page underneath each other instead of in sequence (I therefore used just one static image here).
HTML editor not available by default (or this may have been a user error) - easily fixed by unticking "Disable the visual editor when writing" in my Profile settings.
After creating a child theme via the Child Theme Configurator plugin, all my settings under Appearance > Temptation Settings were lost & had to be re-entered (not a problem if you create a child theme from the get-go, as I should have done).
Hover effect on image thumbnails, whereby they turn to grey-scale & zoom slightly, only works in Google Chrome, not Firefox or IE (I also tested this with the official demo).
I note that the official demo on InkHive's site, as at May 2016, is still running on WordPress v4.4.3. Perhaps the fact that I am using the latest version (4.5.2) may explain some of the inconsistencies?
I must admit that I haven't had to work much with Customize, so cannot make any meaningful comment regarding photosite.de's concern. But the theme also provides a "Temptation Settings" area under "Appearance". I found the many custom settings available here all worked fine.
So, provided you are prepared to work around the few inconsistencies listed above, I believe this template is still very worthwhile.
My non-commercial photo-portfolio effort, using Temptation, is at http://photos.elementfx.com/