Edited to add more information:
Well I finally decided to get a 4 post lift after looking for about 2 - 3 years, plus waiting for the right price
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My two car garage construction is older, late 1970's vintage with only a 9' height to the rafters, not "oversized like newer garages. So in order to get full lift height I had to open up three rafters over the lift by adding additional supports and trusses to redistribute the roof load in that area.
Fortunately I planned ahead when I had the garage door replaced last year as I had it mounted as close to the rafters as possible which allows me to lift the top car almost full up and still have room for the garage door to clear when open.
The basic 4 post 7000 pound (storage & service duty) lift as supplied by most of the USA suppliers, from my own personal observations, are three or four types of designs, an outside column guide (1st generation), a C channel with enclosed guides but exposed cable and locks lifting on one corner of the column (2nd Generation) of which those seem to be the exact same design but made in USA or China, same thickness of materials, same specifications to the working hardware. They are entry priced from about $1895 to over $3000. Many are "pre-fabbed" in China and assembled or completed in the USA. Others are completely fabricated fron raw materials in the USA.
Closed off columns are in two styles, first of which is done by adding sheet metal to the outside of the 2nd Generation column post as a safety guard to the cables and lift locks adds quite a bit to the cost that I did not feel was needed as it does not add strength.
The latest design (3rd Generation) seems to be an all new C column that hides all the cables, guides and locks inside the structure, and moves the cable loading point to the center of the top plate for higher degree of lifting strength and stability, considered to be the "3rd Generation design" and may be a safer lift overall.
Runways seem to be or two designs:
1. a formed one piece diamond plate about 19" wide and the length of the lift having most of the weight carried by the top plate supported on the ends and bolts through welded square or "L" channel bolted to the lifting bar;
2. dual I-beams for each runway length with a diamond plate welded or bolted onto the I-beams.
I like to keep an eye on the condition of the cables (that also very in size and load rating), locks, welds and adjustment of the linkage so I bought a 2nd generation style, and the cost was lower. But If a sale came up on a 3rd generation lift when I had the need, I probably would have bought one.
After comparing features (some have 10 stops, some 9, lift height and width, etc.), included options, material quality, warranty, delivery costs, etc, I settled on a Benco Equipment Pro Park 7 A 2nd generation lift design as it was one of the narrower units that I could fit into my two car garage and still get two cars wide. Many of the other ones were 10"-24" wider or more which meant I would have lost the width to park a second car beside the lift. Most suppliers will charge you to "narrow" the lift to your specifications from $200 to $500.
The real cincher to the deal with Benco Equipment was that all the extra goodies were included in the base price of $1995, being 3 poly drip trays, one jacking tray, 4 lifting casters on lever arms, "light weight" ramps that seem to me to be very heavy duty, more than enough for my cars.
Delivery however was the absolute pits. When it arrived in town the trucking company dispatcher called me to tell me they did not have any equipment to offload it into my driveway eventhough I paid for the residential delivery service. 15 feet long and 24 inches square on the ends weighing in at 1600 pounds, needless to say it would not fit on a standard Tommy Lift gate. So after some careful thought and discussions with Benco Equipment service, my engine picker and chain was brought out of the garage to lift one end, a refrigerator dolly under the other to nudge it out onto the lift gate, then all lowered top the driveway. My advice here is to make absolutely sure the trucking company has a fork lift to offload the package if you pay extra for "residential delivery service", or make sure you have the equipment at your place ready to do the unloading yourself. Don't take the word of the equipment supplier that the trucking company can do this as they probably can or will not. In most cases, a "residential delivery charge" is just for the trucking company to drive into your development or driveway, not do the unload.
Setup was straight forward. I am the anal retentive type who needs to do it all himself, so it took me about 4 hours to get the 1600 pound mass of steel unpacked and assembled in the garage bay. A second person with a strong back would have been very handy to unpack and set pieces in place. With two - three people, you could probably assemble it all in about two hours. Get your local club buddies to help out. I had to use a block and tackle to get the cross members loaded into the coluns that two people would have done in a few minutes. Fortunately I did not blow out my back working smarter not harder.
I am not commenting on the reasons why the Corvette Owners lift collapsed, but from what I have read on lift collapses, it seems to me there are a few main causes I have heard about:
1: the lift is lowered without having all 4 post locks released, one lock holds position, the weight shifts or cables run off the rollers and collapses the lift;
2: people have the lift at the full up position and then do some real jostling and rocking of the vehicle, or overload the rack. A key to remember, these are sold as storage lifts in reality and if you are going to do any serious service work, buy a 9,000 - 12,000 or 16,000 pound lift;
3: lack of preventative maintenance, one of the guide blocks in the column breaks due to getting jambed due to no lubrication or from #1.
4: installation on an uneven surface. Some garage floors are sloped, some are very uneven and a 4 post lift needs to be installed on a flat floor with no more than 3 degrees slope. Shift the load on an uneven surface and it surely will shift, possibly collapsing.
Work within the limits of your tools and they will serve you well.
All in all, I am real happy now that I can perform regular service and repairs on my car and not kill my back or be laying on cold concrete trying to get room and reach for tools. For example, differential out and in about an hour, where before it was 4 hours jacking, cussing and crawling!!
Had I waited for the right sale or had another $1000, I probably would have gone with the latest design 3rd generation lift.
Final Advice: Go and look/touch the lift before you buy it, ask for references, talk to the people who have bought them and used them for a while.
Just my $0.02 for the day.
Cheers!