Do Apex or Nova add any other interesting features and which would you recommend ( note I haven't looked em up yet) and are they paid for or free? And if free, do they contain unwanted ads or push messages like loads of free apps do?
They're free and paid for (for certain 'premium' features like the little number tool tips on icons to say how many unread messages etc.). They've so many extra features I couldn't even hope to list them all out here, but one of my personal favourites is the ability to set different grid sizes and icon/text sizes etc. on the homescreen and app drawer. Feels so much quicker having a 5 x 7 grid in the app drawer for example.
Things like scrollable dock, forced resizing on most widgets whether they 'support' it or not are all free too.
No ads or messages or anything, they're brilliant, I wouldn't use Android without Apex/Nova these days.