High Performance B&W TV

[maxhifi]

This one is for the guys who are either old timers, or have a fair sized collection.

What is the highest performance B&W TV from the mid to late 50s?

By high performance I mean all features which contribute to picture quality. Sharpness, contrast ratio, geometry, etc. Sensistivity is less of an issue these days with the death of OTA broadcast.

As someone whose main exposure to tvs of this era comes from reading old magazines like Radio & TV News, my guess would be one of the souped up RCA 630 clones from the mid 50s, with a 21" picture tube, would be the thing to look for.