Is the Modwright for an Oppo udp205 worth it?

There’s nothing you can achieve with a mod that you cannot achieve with a separate DAC which you can run straight from your Oppo. Probably less expensively, better SQ and with way more choices and flexibility. For the price of the mod you can get a great DAC. That system will also hold its resale value a lot better. You can get a DAC with tubes if you wish, but best place for tubes IMO is at preamp or receiver level.

What DAC would u run from the Oppo that would work better? 

Get a tube preamp like Schitt Freya+ and see if you like the tube sound. This will be much cheaper approach since you can easily sell the Freya.

I like the approach that you're saying. But I like how versatile the Oppo is. Especially with all the formats. Have you heard the Modwright Oppo?  I know things look good on paper but can sound so different in reality.

I bought a Modwright oppo udp205 right after they were released and have been absolutely satisfied with it. Before, I was using a standard oppo bdp-103 that had great sound, but not close in comparison to the udp205.  (The idea of prior listening to an un-Modwrighted udp205 never occurred to me, and how could I have objectively compared the two after the time-span gap it would have taken to perform the modifications...?!)
Nevertheless, the sound quality is superb....there is a solidity and tonal purity when playing pureaudio BluRay discs that I had never heard before, and since I listen through a pair of Klipschorns (CJ preamp, modified Hafler amp, anticables, premium audioquest interconnects), I pretty much hear it all. The Sgt. Pepper Bluray will leave you astounded!

One thing that is CRITICAL to getting the proper sound from any oppo disc player is the configuration.... so immediately open the setup menu and configure it to your particular speaker setup, etc.
The udp205 comes factory-supplied to provide 7.1 sound; if you have only two speakers, etc. I guarantee if you don't do this that the first time you hear it you will be underwhelmed....that happened to me.  I was quite confused/upset by my udp205 upgrade purchase until I took the time to follow each step in the user manual.....and once I performed those steps, I was completely sold by how amazing the Modwrighted player sounds.
(These multiple settings, including the distance from the listener to the primary speakers, also allows you to set the "Crossover" which "allows you to set the Bass Management kick-in frequency for all speakers."  This setting can be changed while you listen to music, and the the results may surprise you....different discs for me alternate between 60Hz and 80Hz for the best sound.)