The last one that I bought, the deciding factor was "would it fit inside of my car".
I had decided to buy a recumbent trike to match my wife's. We loaded her trike into my Honda Element and picked one out. After a short test ride I told the bike shop guy "If you can show me how I can make it fit inside of my car, I'll buy it." It took about three attempts, but we eventually found a way to make them both fit and I bought it.
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My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.