I upgraded my home office setup to Pro after toying with the express version for about a month. Expected some of my issues to be resolved, but they simply were not fixed by going pro. For me, it was $500 wasted, completely.
One of the biggest issues you’ll find is intellisense for UE4 coding. Both many users and Unreal themselves have recommended Visual Assist from http://www.wholetomato.com/ Had a few other minor issues which are irritating not in a deal breaker way but in a “$500 software shouldn’t be like this” kind of way. Intellisense is the big issue.
You will need Pro in order to use this VAX. I am personally still struggling with the idea of investing even more money into it, but if you are just starting out, maybe consider the Pro cost to really be $600 with VAX. If you can deal with bad intellisense, then stick with express and put that money into something else. I also expected some improvements with the UE4 VS plugin as well, but have little reason to use it so far.
(My background is .Net and ASP in my day job. Pro is great for this use and would fully recommend Pro for anything in these languages.)