My Oppo is a bit too bright

I agree with some of the other posts that suggest the OPPO's use of the ESS DAC chip is potentially the primary reason your impartial listeners found the sound a little harsh. This is not contradictory to the fact the OPPO analog output is very good or that the player is an excellent product and outstanding value. Many people like the strengths of the OPPO analog output and of the ESS DAC chips.

But if someone feels there is some harshness or listening fatigue which outweighs the other parts of the ESS-based DAC sound, then a very common alternative are the AKM 449X-based DACs because just like the ESS the AKM chips are used a lot. These also produce very good sound but along with potentially sounding less harsh or fatiguing there are other aspects that will sound different.

Obviously this is a generalization of implementations of the ESS and AKM chipsets, and there are some products where this characterization doesn't strictly apply, but on balance I feel this is a reasonable starting assumption without additional information about the DAC design or without having heard the DAC itself.

Thank you all for your comments. To recap:
1. The Oppo’s DAC is its weakness and I should look for an external DAC
2. The Oppo’s DAC is quite good and can’t be bested unless I want to spend more money then it’s worth.

Fortunately this can be tested.  You can demo DACs like the Audio Mirror Tubadour Mklll SE or MHDT Orchid, etc. at home as they offer trial periods.  I’d think it’d be well worth your while to take advantage of this, and I’d be very surprised if you didn’t hear significant improvements.  FWIW.

Buy a dedicated cd player....the oppo is a do everything wonder, but not designed as a dedicated cd player and therefore is a compromise to fit all that in one box. It’s a great product, I own the 205. Better yet, get a cd transport and the dac of your choice. I’m using both a Marantz space saving cd hd1, as well as the audiolab cdt6000. For dacs, I use the musical fidelity v90 dac and a jolida glass dac, both top rated dacs in their respective price ranges. Another great dac would be a border patrol. But to be honest, when I really sit down and listen, I'm listening to LP's, analog. 

By a $50.00 tube pre off Amazon and line stage it.

Suca 1 Preamp!

Be amazed!