what are the advantages between the two, which do you prefer, do you dislike the flimsiness of all Swiss lace and choose a French base for that reason, or is all Swiss better because it feels lighter?

All swiss is less detectable to the touch.

French wrinkles a bit more easily.. especially on non-custom pieces that are not made from a good template of your head shape.

The join b/t the two materials annoyed the heck out of me. For that reason alone I will never go to a piece made out of multiple base types.. But, hey.. a lot of people like that. I wear my hair really short, so maybe that's why. I think multiple base materials are better for people with longer hair styles were touching the base edges, etc is much less of a worry.

Sometimes the join can break a bit over time, causing problems.

If you take care of swiss it will last just about as long.

Just my 2 cents.