Why not just stick with SR4 or 5?
I liked both.
Just like people generally stuck with DnD3.5 when 4 came out (and was rather... uhh, let's not get into that, maybe).
I haven't played SR6, yet. What did they do?
SR4 and 5 to me have just the perfect amount of complexity. You get invested in your character (because you actually need to spend time on creating one) and have lots of agency in how you create and evolve your char. No class restrictions (other than Mage/Adept/Mundane) so generally very flexible.
Magic is done just perfectly, without that inane "can only cast X spells per time period" while still having a cost to casting spells that you have deal with.
Combat is also great with the two damage tracks and how receiving damage actually makes you fight worse.
And, oh man, the things that can be done with cyberware and how it interacts with magic. Nice.
The only real differences between 4 and 5 are the limits, IMO. Other than that, 5 only had minor changes over 4, should've been a 4.5 really.
Did they somehow manage to mess all of that up in SR6?