There was a debate once here about this prduct. I don't remember where, but now, search function is broken for old posts sadely :-(
I won't recommend this one, better stick with a dual stage + good needle valve. This electronic device is based on speed of membrane to shut-open. When pressure will change, as they claim, speed will be the same, but definately, CO2 flow will change. Number of drops won't change, but probably their size, because of changes in flow.
I don't think they implemented a dual stage build for pressure compensation because the regulator is too small. If they did, it would then be a nice product to replace needle valve and bubble counter.
I emailed them with this issue and they never answered me.
Let you decide... but this product, in my opinion, will only solve the appearence: a constant bubble number but not a really constant flow as dual stage regulators