My favorites have been Finish Line Ceramic Wet lube and Triflow, they have been ideal for the vintage all metal machines. These are the only two I have noticed giving a notch or two of extra smoothness. I have to admit, in most cases the basic oil will get the job done and work just as well. Even frozen and sluggish machines run fine after an over night soak. Stubborn cases often takes more time even with several fancy products on hand. The aerosol are safe and will work. It's ideal for clean up jobs, dissolving and flushing out grime and dried up oil. On a resonably clean machine there might not be much of an advantage. The only disadvange with spray can stuff is they are much thinner and dry up quicker; which will result in hickups; I have had the feed dogs and stitch length setting on a few 66s and 99s act up and it was because I thought the spray can oils at least were acceptable and would last a bit, but not even two days in the worst of case. A factor might be that it's not the spray can oils causing all the problem, but dried up oil and grease partly dissolving and not being flushed out. When the light spray can oil evaporates the machine gets sticky again.