Oh sorry, I didn't think anyone was that interested in it.
The boro balls arrived and the conversion went smoothly. Had a bit of trouble with the 4 mm balls not arranging correctly after dropping them in, but after a few attempts it worked out.
After closing everything up again, I did a dry run by ramping up the temperature to the max over the course of one hour. The idea was to check if the expansion of the glass would cause problems and also to (hopefully) vaporize any impurities.
As someone who enjoys longer sessions, taking a sip here and there, I didn't notice a huge difference to be honest. The biggest change was the temperature scale. I used to start with the knob at 9 o'clock and slowly work my way up to around 12-1 o'clock.
Now I start at 7-8 o'clock, and when I get to 12 o'clock, the taste is already pretty roasty. So I guess the device is now more energy efficient, which is nice. Ideally I would adjust the high and low temp settings, but unfortunately my EU version doesn't have the two potentiometers to perform that adjustment.
Apart from that, I think that the flavor profile of the herbs got a bit more complex. Could be placebo though.
Draw resistance is obviously more restricted after the modification.
In summary, I don't know if the conversion was worth it for my use case. It might make a bigger difference for people who enjoy a couple of huge rips through water, but that is not me.
I did take a few photos, but honestly, the device looks exactly like the VB1.5 on the Vaporbrothers homepage.