I am using i5-6300HQ at work and i7-7500u at home. Both 12GB of RAM. Although the CPU bench marks are pretty much similar or even i5-6300HQ seems better, i7-7500u is way way faster than i5-6300HQ.
I previously used i5-4310u at work. i5-6300HQ is not much faster than i5-4310u. I use Google Chrome, Outlook, Word, Excel, Microsoft Visual Studio, SourceTree, etc. at work (like typical software engineers). Both i5-6300HQ and i5-4310u are very slow and stressful to me for my work. Both computers often caused problems with VMWare Workstation Player.
I also have a computer with i7-4700MQ with 12GB of RAM. i7-7500u is even faster than i7-4700MQ. I compiled same source code with Microsoft Visual Studio 2017 on both computers. Since it contains multiple projects, compilations are done simultaneously in multiple threads. i7-7500u is always the winner even though it has only 2 cores where i7-4700MQ has 4 cores. Very interesting result.
But if I watch Xfinity TV on the Google Chrome browser and do some other things like Microsoft Word on i7-7500u, it gets very slow like snail. It's almost unusable. i7-4700MQ doesn't get that bad.
Quad core i7 will be the king. Forget about i5. If you want longer battery life over performance, i7-7500u is a good compromise.