I'm thinking about replacing my over 30 year old Toro S200e that, is sort of falling apart, with something used, at least as low maintenance and built at least as well. What are the differences between the S200e, S620e, CR20e & Snowmaster 20e?... did I leave any other similars out? I'm not sure what vintages all these other models are other than I do know the S620e is the successor to the S200. Did build quality suffer at all in the later replacement models? Were there any improvements worth considering? Is there another model worth considering? Are there any good quality 2 stroke, 2 stage blowers worth considering? In Chicago, we may get a couple big snowfalls per season but most are perfect for the likes of an S200 so the priority would be the better, lower maintenance machine over the blower vs 2 stage feature being the deciding factor.