I have not heard an ET-5, so take this comment with a grain of salt... I'm just throwing out another option.
I had a c-j PV-14L for a lot of years. It's kinda entry level c-j, but a good performer for the money. I bought it new. A couple of years ago, I decided to upgrade to a used c-j Premier 17LS2. It ended up having an issue and I opted to return it rather than trying to get it fixed. I did have it for a couple of weeks and I bought a bunch of 6922 tubes while trying to trouble shoot it. Still have them....
Anyway, I ended up with a Linear Tube Audio MicroZOTL preamp level 2. I personally prefer it over the c-j preamps that I had. Tubes last a long time in it.