I'm looking for a replacement chainring after crashing and bending the current outer ring. I have Rotor 3DF cranks, with the inner ring a NoQ 39t of a 53/39 setup.

Would any 53t chainring work? Assuming I go with same specs (130mm BCD, N10, 5 Bolt, B-Type)?

Also, I see that the Ultegra chainrings don't look like they have the visible bolt holes that other rings have... are Shimano rings off the table?

Chainrings generally come as a set, because they have ramps and pins that line up to facilitate smooth shifting. I know that with my Praxis rings, they explicitly state that the large and small rings only be used with the other ring of their set, no mix and match. Other manufacturers may be different, I dunno.

I searched around, and dang, that 53T NoQ ring is 'spensive.

Yeah... I found the Rotor 53T couple weeks ago on eBay for $45 and didn't pull the trigger... kinda regret not doing that. Not burning a benjamin for one though.

It depends how fussy you are about shift quality. Any 53T ring that will fit with ramps and pins will shift okay - but vary from pretty poor shift quality to excellent. With indexed shifting, do not attempt to use a ring without ramps and pins.

That's good to hear. In terms of shift quality, is it just a matter of trial and error, some brands working well with others while others work so so... or is it generally the better quality chainring, the better shifting it has, regardless of brand?

I saw a SRAM Powerglide 53t that said it was compatible with Focus and two other levels, but wasn't sure if Powerglide was a proprietary system meant just for their own setup or just marketing jargon.

Thanks for the info btw