One point to be aware of with feature toggles: if you're using them as a substitute for branching and merging in your VCS, you're deploying code into production

One point to be aware of with feature toggles: if you're using them as a substitute for branching and merging in your VCS, you're deploying code into production that you know for a fact to be buggy, insufficiently tested, and incorrect. If your feature toggles themselves have bugs, or don't properly isolate your new code, you could easily run into problems up to and including data corruption. You may be switching your controllers on and off, but are you also toggling your static assets such as HTML, CSS and JavaScript? People are often scared of feature branches because of large, tricky merge conflicts. However, large, tricky merge conflicts warn you (noisily) of problems such as these before your code gets into production. Problems with feature toggles, on the other hand, don't show up until after your code gets into production, by which time it may well be too late.