I´ve had my Temperas on for a week now replacing EPW EA and Bel Canto DG. Great volume arco and especially pizzicato, great sustain, clear notes and great feel - low tension but not flobby. Nice gauge - D and G a bit thicker than EPW, E and A a bit thinner.
On my arco bass they sound quite bright and spiroish arco but with more sophisticated colour to the sound. They haven´t yet mellowed down and I still have difficulties to get a clear start of a note with open strings. Especially the A is scratchy. G is my favourite. It´s very easy from down to high thumb positions. I also get buzzes from fingerboard.
In a string orchestra rehearsal I felt I was lacking the bottom end and power on the E and A. Me and my 1919 Bohemian like EP weichs better on E and A. Maybe I leave the D and G Tempera on, wait for them to get darker and try to mix with Evahs.