Who said I endorse Cessna's figures either?
How many buyers do you think would write a check exlusively based upon website information anyway?
Too many that I know. That's where a General Aviation Aircraft Analysis comes into play (and it has to be done by an independent contractor, not by someone employed by the manufacturer).
Maufacturers begin with target performance specifications that are adjusted a result of product testing. Too great a downgrade will send buyers to a competitor, one of the risks manufacturers take when setting the bar too high initially.
Traditionally, manufacturers put the best face on their products (otherwise known as lies). Real results, or performance, are almost always different and almost always well below their published specifications.
One final note, buying used (as opposed to new and untested) is almost always the safer bet. There is, in my estimation, a five to ten year shakeout period on any new airframe that will reveal design flaws that may not be observed during certification. A used aircraft (one that has gone through a few annuals or a TMO schedule) is a better money maker than a brand-new, sexy, little thing that spends more time in the maintenance bay than producing revenue or value.
"buying used (as opposed to new and untested) is almost always the safer bet"
Very good point, this is also why I don't buy first year automobiles.
I'm not yet sold on composite construction which many of the new designs employ. Even though aluminum is subject to corrosion and fatigue, those characteristics are well known and have been studied for decades.
A problem with older light jets is the fuel economy and cost of engine overhauls, Citation I's and II's are good examples. Older Turpoprops are more fuel efficient but slower, both the Conquest I & II are good choices with the King Air a possibility except for its slows cruise speed and most have high hours. All of these options are planes in the 20 to 30 year old range too.