The NAPA Golds (Premium) made of Belden wire are EXCELLENT.
Some of the sets in that series use a fiberous/paper like core for superior conductivity.
Boots where always solid. Wire had a nice sheen and was coated, not simply a 'dry jacket'.
I have not used or installed a set in a really long time, but the above is what I can report. Excellent cables. Very expensive if I remember.
As far as Bosch, if they are real Bosch (German made), no doubt they should be good, but these days, Bosch lets people stamp their name on anything.
The wires I am refering to, did have the word 'Belden' all over the wire. I believe they have a line that is not made of Belden wire.