I have a pretty decent milsurp 8 x 57 Mauser, actually a Mannlicher-Schoenauer action--the G98/40 Mountain Carbine. I have pondered getting a modern bolt gun in the caliber and adding a glass sight, but with a very nice 30-06 and 9.3 x 62 (both Mauser 98-series commercial actions) the need to do so is pretty hard to justify.
The USA ammo companies haven't been kind to the 8 x 57. It has been greatly under-loaded in factory form; European loadings equal or slightly surpass factory 30-06 ballistics. It was INSTANTLY accurate and tractable with cast bullets for me; it has been very obliging and forgiving. It might be "one of them furrin' numbers", but it is one fine caliber that is excellent for all North American big game. It is truly Europe's 30-06.