Dude's 6SN7 replacements with Chinese CV-181/6SN7

After about 3 months of breaking in the Dude, I think it's time to do some 6SN7 tubes rolling. I know this topic has been discussed before but I missed the thread.

Instead of the NOS 6SN7 tubes, I am thinking of trying the Shuguang CV-181Z or the Sophia 6SN7. Both are very similar prices at about $200/pair.

Have anybody tried any of them before with your Dude preamp?

Any opinions or suggestions are welcome.