I don't have one but have used one for a weekend.

Absolutely terrible design and useless charging abilities.

Because the stove is closed at the sides the only way you can feed it (which it needs a LOT of small twigs to keep burning) is from the top, yep the place where your pot sits.
So it's an absolute nightmare to keep fuelled up which is bad enough, even worse is the rate of twigs it goes through with the fan on.

I tried keeping it burning for 30 mins and in that time my S3 did not charge even 1%, i'd sooner run home charge the phone and run back rather than keep the stove fuelled for hours on end, which sounds ok except i was over 100km away from home

It's also very heavy compared to other stoves and extremely bulky.

Lastly the fan stopped working on the second night on the one i borrowed.

I wouldn't take one camping again if you paid me €250