I have the Mann Lake 18/9 motorized extractor, it is all stainless and very well built. The Mann Lake you are looking at, I looked at the instructions for it and it is all stainless. I do not know what your sale price is but there is only about $150 difference between the one you are looking at and the 18/9. If that is the only difference I would definitely go for the 18/9. 8 good hives can produce over 20 medium supers in a good year. Having the 18/9 would really make a big difference with that many supers. I have 9 hives produce over 50 medium supers in one year, 3 different extractions.