Not sure what that first sentence means...
The second, -Not really, the oil less SS compressors can be 4X's as loud as a lubricated unit.
What the first sentence means I that you normally don't see 'super quiet' pasted on the box of a single stage compressor. I expect them to all make similar noise. And you are right, the oil-less compressors are the most noisy. But I ruled them out because the OP was referring to a 60 gal tank, which I have never seen an oil-less compressor in that size.
So 5,000 hours compared to 20,000 hours is a big difference. For me, just a weekend garage user, here is how I do the math. I spend on average 1.5 days a week in the garage or 12 hours a week. Multiply that by 52 weeks a year and I get 624 hours of garage time a year. I will just round this up to 700 hours a year. Now the compressor won't be running that whole time. I have a blast cabinet as the heavy air user amongst other air tools. I will say that the air compressor will run 30% of the time I am in the garage (that seems like enough). So 30% of 700 is 210 hours of use a year. If we take the 5,000 hr life cycle and divide it by 210, I will get 23 years of use. At that point I would be more concerned about being able to find parts for the compressor after that many years. So I would look at who makes the pump and look at their record for long term support of products. If I were running a shop, I would look at the 20,000 life span.
Besides bearings, I see most people replacing reed valves. You may want to look at the pump design and make a determination on that. It may have great bearings but if the reed valves or piston rings are being replaced every 2 or so years, that can get expensive. I don't know much about the pump, but I think the cobalt uses a Campbell Hausfeld pump.
