pro "amateur" lvls of editing, rendering, programming, modelling, encoding the i5 will be fine, since its not where you spend the majority of your time anyway, gaming will see 95% the same performance as i7, because only very very few games take advantage of i7
for "medium" lvls of editing, rendering and so on, the i7 will definitely help because the i7's hyper-threading will speed that process, and you find the cost worth the performance/time gained
for "professional" lvl's of editing, rendering and so on, you want an entirely different socket CPU, with more cores and threads, than even 6700k has, because you will be spending most/alot of your time on this work, and the benefit to cost becomes greater there more your workload increases
for casual lvl of gaming/streaming and rendering/editing, there is truly no reason to take an i7 6700k, unless you have the extra money to spend on nothing better and just want "the best" of teh 2, then by all means spend the money
the extra 100 bucks from i5 to i7 could help increase your GPU instead, which would prob be where the majority of your use and time would be spend, thus the biggest gain