I bought the i7 first it ran quite hot the battery life was crap, fan noise was only an issue when pushing the machine. I returned the i7 mainly due to poor battery life for my uses.
I then bought an i5 which has better battery life for me and does not run as hot at all but it still can get quite warm. I liked the i5 11" MacBook AIr I bought 2 😛
The i7 may be worth it for some people but the tradeoff just wasn't there for me, I love my i5 11" Air - It is my favourite Mac ever...