Seeing as how ironic this morning is turning out to be, maybe it's ironic that this thread isn't about irons...
One of the mystifying and ironic (to me, anyway) oddities of mass production is that, regardless of precision methods and quality control, still... no two things are exactly the same. Whatever brand/ model you consider/choose, there will always be that small chance that you could wind up with either a lemon or a Winchester '73 (that 1 in a thousand "perfect" machine that's better than all the others, for lack of a better analogy). You can never tell from the sales floor or the box; it takes experience using the machine (or whatever) to determine things like that.
So we (humans/savvy consumers) tend to somewhat base our judgements, and go on, empirical data like repair records and opinions/reviews of others. But like investments and gambling, probability and statistics warn us that "past performance is no guarantee of future results" or something like that...
So what the deuce is Doc on about this time...? Just this: Choose a machine based on what features it has/you like/want, bang for your buck, budget, etc., and by all means, test drive as many as you can. But base your decision on what you know rather than what others scare you into thinking about what might/could happen or even what's happened in the past (if it's because of bad luck). If you get one you're not satisfied with, return it and keep trying (satisfaction & service are worthwhile criteria) before giving it up for something else that isn't really your first choice. Never settle for a lemon, but if by chance you find yourself in possession of that "'73", enjoy the hell out of it. ;-)
Everyone is anxious to just go get a machine (or whatever), pull it out of the box, and be able to dive right in... Our internet/instant gratification culture has made us that way - given us those kinds of expectations. Maybe SMs should be that way - maybe not - I don't know. I know that life, good decisions, and long-term satisfaction often require more time & patience than we first expect.
Doc
Something else to consider about noise. Machines (of all kinds) often sound quieter in a store - because of background noise, acoustics, voices explaining things & answering questions, passing traffic, the airport nextdoor, etc. - than they do in the relative silence of your home. The difference in the frequencies (pitch) of the ambient noise can also make the noisier machine sound deceptively quieter and vice versa. (Think about that one.) The only true test of how a machine will sound in your home is to try it there, which may or may not be practical/possible. If the machine I really wanted were just a little noisy, but that noise was not indicative of some defect/problem and would not effect function or wear, I think I might invest in a good set of headphones and put on some bluegrass... YMMV. ;-)