There seem to a few minor iOS7 issues below but none are showstoppers.
there is a line wrap issue but also a temporary workaround (more of a hassle on smaller screens).
http://omz-software.com/pythonista/forums-old/discussion/1435/wrapped-lines-not-displaying-correctly
Entering a tab results in just one space going into the editor regardless of the spaces-per-tab setting. The workaround is to just enter 4 spaces as recommended in PEP8.
Apple seems to have tightened up the sandbox constraints in iOS7 so code such as os.listdir('/Library') works on 6 but not on 7.
there a strange issue with roundtrip use of pythonista:// with external browsers (this one is rare and needs further investigation)
http://omz-software.com/pythonista/forums-old/discussion/1452/ipad-4-ios7-url-scheme
I have been using Pythonista on iOS7 since it was released with no major issues.