Ethernet to SPF converters. What's your experience?

I think cheaper is better, but where the AC adapter is matters.  If it's near your equipment or sharing an AC line, keep it on the "dirty" side of a power conditioner and consider an aftermarket supply like these.  They won't make the network connection better but they will reduce the amount of noise in your AC line. 

Thank you for all of the suggestions. 

I’m very familiar with the sound when connected directly from router to streamer via ethernet.  I’ve had it that way for a while. I bought the switch a couple of weeks ago.  So far, I like the sound with it.  I’ve only spent a few hours with the ethernet to fiber converter.  Jury is still out on that.  The little wall wart is plugged into the same power conditioner as my other gear, so that might be a problem.  I’ll look into that.

@boulder_bob Yes, the LHY ock-2 clock has three outputs for square wave and three for sine wave (I’m using square wave).  "more relaxed" is kinda what I’m hearing with the converter, but I’m not sure if I prefer that.  I need to do more listening. 

I have two systems on fiber. Both use switches with built in SFP fiber ports and both my streamers accept SFP fiber inputs. Definitely a lower noise floor. Before all that I tried those 2-piece ethernet to fiber converters, but too many connections nearly erased all the noise stripping that fiber does. So I bought the switches and streamers that had them natively. Much better. Lower the noise floor, blacker background = better more detailed audio. Btw, the AOC SFP modules are the best. 

Yes definitely isolate the wallwart from audio. 

I’m running Nucleus One and a basic Trendnet Switch. Nucleus is plugged into a dedicated circuit 1, system (DAC and integrated) are on dedicated circuit 2. Switch is plugged into a completely different circuit. 
The Trendnet switch, to my surprise, smoothed out digital glare when used with Nucleus. I’m also running WireWorld Starlight 10 Twinax Ethernet cables from eero to switch and from switch to Nucleus. That was a very good improvement as well. The WW Ethernet cables are really good. 

Been using SFP's for years and will never go back. Only using quality converters from Edisoncreation and Sonore Optical Module Deluxe, with Afterdark LPS,