Question about Einhell GC-CT 18/24 Li

I agree with "maniue20" as I use both. Thread cuts a larger radius. The disadvantage is that you can hardly find the thread remnants. Plastic knives that have fallen off often bore into the material, but you can find them - even later ;) - well.
Large is of course relative.

Large areas are also possible. I think the plastic knife is better.

Knives are sufficient for small jobs (small areas). The thread is more suitable for coarser work (large areas).