I won't respond to the Bauer/Coltri comparison as I am not a dealer for either.
The Kidde military compressors have been the standard of the military weapons business since the early 50's. I have modified these military compressor since building my first one in the mid 50's. They are extremely durable, very reliable but like any other machine -- occasionally a lemon. They can be very trying when not working. BUT that said -- over the years I have sold more than 1000 of these units and have had to eat maybe 25. They are becoming very hard to find and I probably have the largest inventory of parts in the US except military repaiir facilities and they don't sell them to anyone.
Many are coming out of storage because some older person bought it 30 years ago and the kids found it and are trying to sell it or get it out of the way.
They are small, compact and excellent compressors but limited to 2.4, 4.2 and 6 cfm. They easily pump to 4500PSI
American Bristol compressors were fabricated by ABI in California for over 30 years They are a Hamworthy block but now parts are very difficult to find. They came in 3, 5, 7, 10,12, 16, and 25 CFM sizes. They were the standard for fire departments in the 60's70's and 80's and later until Bauer and Mako got serious about service and quality (MY editorial license). The best size compressor is the 4S7-60/70. Extremely well built machine, long lasting and very durable. Recently we have started to make gaskets, rings, valves, and critical parts for this compressor since Bristol/Hammworthy no longer supports the product. I am selling these to scuba and CNG customers.
Jim Shelden