it really all depends on:
1.what you're gonna use it for
2.what your other components are like
3. and how long until your next upgrade
Ok so basically the Ryzen 5 3600 is the same as the 3600x with the x version being slightly (avg 2%) faster than the non x version. it also has a slightly higher clock speed
If you're using it for gaming or anything like that you're not going to see any difference (Exception to be added) the same goes for School work or typical office work.
the expection that i mentioned would come about if your other components are completely OP like the latest GPU, a ton of ram and all of that... otherwise no dice.
Like i said, your other components will determine if you actually get any improved usage (Noticeable). so if the rest of your rig has mid range items like a gtx 1660 or 16 gb 3200mhz ram then you wont feel the difference, unless you run a benchmark and read a bunch of stats.
Lastly, if you pnaning on keeping this cpu for 4 or 5 years or less, and the rest of your gear isnt top notch then don't bother. however if you're not gonna upgrade for the next 10 years or so then it might be worth going for the 3600x since the price increase would be just about 2 euros a year.
In the end it's really up to you, but i recommend you look at this user benchmark site - it's very good (in my opinion) :
https://cpu.userbenchmark.com/Compare/AMD-Ryzen-5-3600X-vs-AMD-Ryzen-5-3600/4041vs4040