Ascetic integration — Different nodes, redo assets (re-wire textures)
Stability — Closed without warning or errors (Just after hitting F12)
Features — No Prinicipled shader, no Metalness (eh?), does it mean no PBR? No Glossy/Spec?
Features 2 — No displacement (duh?)
Caustics — 50/50, as it was late, I tried, it crashed
Overall, my revelation was more like this is a square wheel, not a production render.
Why use it over Cycles
F12 crash blender ? You should report bug if it is not done. If already done with the problematic blend file thank you.
Principled shader will come after GI caching in luxcore 2.2. Same for Displacement. Theses features integration can be faster if we had another Core dev ( Dade is alone in this area currently) perhaps you can help to find a Dev to join the project ? Who know a friend with c++ coding ability ?
About shading capability Luxcore is able to simulate almost 99% of physical phenomena. You can download example scene on the download page to test and practice if you want.
For caustics it is clear that Luxcore and cycles are not playing in the same league. Just switch to Bidir engine and metropolis for this kind of work. And if you have problem please post in the forum a lot of people will help you fix issue (faster with blend file).
Why you should you use Luxcore over cycles ? Why you should have to make a choice ? They are both free and opensource you can install luxcore side by side with cycles without problem and then when you will have a better knowlegde of Luxcore mabye comparable to your cycles level it will be easy for you to answer this question:
Why i should use luxcore ?