Pmboyd,
I posted my reply before reading the entire thread, and particularly your post where you said you had changed your mind, so please don't take any offense at the fact that I posted after you said the issue for you was settled. I would, however, like to add a few other comments regarding my thought process on this subject.
(1) The 17.5 crossover would be simple thing to put back as it was originally, so I decided to take the chance.
(2) I really liked the sound of the stock 17.5s but wanted to see what would happen if I tinkered with the crossover. To me it took the speaker to an entirely different level and I am very happy.
(3) The 17.5 was a $3500 speaker. The pair of Mundorf s/g/o capacitors was a little over $300, and the Mundorf resistors were about $13 each if I recall correctly. I don't know how much the Jie-Deng capacitor that Alan used originally in the speaker cost, but from looking at it I doubt it was too expensive. I'd guess the 2-ohm, 5watt capacity cement resistor probably didn't cost much more than quarter.
Now, from what I have read, Alan Yun is a one-man operation, so this factor may not apply, but if one assumes a 5x or 7x factor for the cost of parts to the final retail price, my little crossover modification might have shown up as about $1700 to $2400 of the final speaker retail price. There is certainly no way that Alan could hit his $3500 price target and use components like the Mundorf stuff I put in. That is, assuming that was his target.
Also, in his review of the 17.5's, Marty DeWulf makes the point that Alan uses really good drivers and operates them within their comfort zone. I respect Alan's genius and that is why I didn't change the crossover component values from what he used.
(4) The speaker house brand at my small local shop is Canton. The guys at the shop now describe my 17.5's as being ballsy like the Canton Karats, but having the mids and upper end characteristics of the Canton Vento Reference series. And as far as I'm concerned, that is a great combination.
But the thing I want to reemphasize is that the change I made worked in my system, and I was willing to take the chance and have the patience to let the caps start to break in before forming any conclusion.
And don't get me wrong, I loved the 17.5s as they were, but the changes I made have taken the 17.5s to a totally different level. I love the liquidity, neutrality, speed, and transparency the s/g/o provides. The leading edge attack and decay of transients is phenomenal, and we are all hearing deeper into the music than ever before.
I would love to get a pair of the 17 Supreme (or Bolero Supreme) speakers with the 330D tweeter... and maybe someday I'll be able to... but if I did, the first thing I'd do is have a look in the back to see what values Alan used in the crossover, and I'd be on the phone ordering my Mundorf stuff.
The pair of 17.5s I have actually used to be owned by Marty's wife. I think he usually uses a Pass X350.5 for his reviews, and I don't know on what system they were played the speakers after his review... or if he used the Pass for his review. All I know is that he loved them. I also know that his partner generally does the tube equipment reviews and he loved the 17.5s, so while I'll add the requisite caveat that the changes I made worked for my tube system, I suspect that the changes would sound good in a solid-state system. You can read their Bound for Sound reviews via the link from the Silverline website.
But, finally, again, the Mundorf s/g/o is very transparent. If your system or source is crap, they are going to jump right up and tell you. But if you have your system dialed-in, then I believe you will be rewarded as I was.