I own a crazy popper aswell, and interestingly enough find the optimal roast weight to be identical to yours - around 150g. The popper does a good enough job for me, even in colder weather (admittedly the 16 degrees I was roasting at yesterday evening isnt particularly cold) and the only drawback Ive been able to find with it is the machines reluctance to be tinkered with. I had to drill through an unused portion of a circuit board to get to a screw so that I could disassemble the thing, and even then it was a real pain to take apart - I can only wonder what attempting to modify the thing would be like (I gave up).
That said, it is a very good stock-standard popper. I got mine for $25 a month or so ago, and it has so far roasted very consistently and much quicker than I expected after reading articles here and elsewhere.