Thanks for the input Steve. You confirm it perfectly with 24" that this OC is no easy guy.

I forgot to write about my own observations:
4": even under early perfect conditions, nothing is visible with the small aperture
16": very good transparency, Auner 1 only around 15° over the southern mountains, visible as a very faint glow S of a 9mag star, difficult to hold with averted vision, triangle appearance, southern edge very faint star chain

Take care when using Guide 8! The star map shows the OC 8' E of the real position, better using a DSS print for searching the OC