Congrats on your O - its a lovely cartridge.
On different phono stages, I've tried values ranging from 80 Ohms to 250 Ohms using resistors from different manufacturers. I think the optimal value is a personal preference and can depend on how 'live' your room is on the top end. The higher values lending themselves to a bit more 'sparkle'. (Not a negative attribute here.)
On the ARC PH7 I used the 100 Ohm preset for quite a while and its simple to switch values with the remote - eventually I settled on 200 Ohms.
After trying different Caddocks, the "nude" Vishay S102s and several others, I settled on 170 Ohm Tantalum resistors for use in the Atma-Sphere MP-1. 220 was a tad tipped up. The S102s are nice and clear, but so are the Tants and they've a wee richer timbre.
Tim