Anybody upgrade their Zu Omen DWs to Souls?

I'm betting my amp will work with the Souls. I really don't want to trigger the need to change it to suit the new speaker. I've corresponded with them about the upgrade logistics and it's about as good a situation as you could ask for. They don't credit you with your trade until they receive/inspect them so it's entirely your decision when to send them back. If you can make the finances work, you can keep the ones your trading while you audition the new speakers (also carrying the 60 day trial period). If the new ones aren't working for you, keep the trades and send 'em back. Can't beat that.

With what information is available, and the generous terms, I decided to trade up. A set of walnut cabinets are already handy so the wait will be minimal. I'll update this when they have had a chance to tell me they do or don't belong in my listening space. 

Interesting. I had done the same with the 15 ohm resistors but with an NAD C368 driving them. As in your case it softened them a bit but didn't give me what I was looking for. I decided to follow the generally accepted path of lower wattage tubes resulting in a substantial, welcomed change. Your point about synergy between amp and speaker is well taken. I enjoy listening to this combination a lot. I would be just fine leaving it as is if i weren't for the full trade in value offered by Zu. 

I'm not sure exactly, but because the walnut cabinets are already on hand I was told they would be ready to ship in one to two weeks. I'll be optimistic and hope for end of this month.  

However long it takes, it's too long :-)

The jury has returned and the verdict is in. Souls win! They needed a couple of weeks steady (10+ hours/day) break in to lose some treble grain, but thinking they had improved enough to decide I did a comparison with the ODWs this weekend and the Souls are very compelling. If you read John Darko's review of them it's pretty spot on. The ODWs are very good speakers, especially for the money, but the Souls are next level good. I had every intention of sending them back if they weren't worth the extra cash, but for me they are.