Could this be because older sims used to have the actual hardware from the A320 installed? In particular the SECs, ELACs and FACs.
On newer sims, these computers are replaced by software simulation. So it comes down to how well this software can reproduce the actual handling characteristics of the A320. (Not great, in my opinion. I prefer the older (CRT screens) A320 sims as well. )
If you look at the Lufthansa training device list, you can see that their sims are equipped with different hardware or software simulated hardware:
https://www.lufthansa-aviation-train...ining-devices/