Post #5 referenced a Zenith 601. As far as Rans goes, I would be cautious
about buying any aircraft where no prototype was built and test flown. Look at what Van has gone through with the RV-12.
Just so everyone's clear... it's not like Zenith just drew up some plans and started selling them without building and test-flying the result first. What they mean by "no prototype" is that the first aircraft was fully "production" representative. The difference is as follows
Traditionally, a true prototype is essentially a hand-built, one-off aircraft; there will probably be only one or two examples. While it may generally be similar to the configuration of the final aircraft (and some come closer than others), it's not really the finished design. This was very common, especially before computer tools and all that were readily available; though you still see it used with aircraft (like fighters) that really push boundaries on performance. The prototype approach allows a lot of data to be gathered and different ideas explored before finalizing a design. Some examples would be the YF-22 and YF-23 demonstrators leading to the F-22 production fighter, or the X-32 and X-35 demonstrators leading to the F-35. In each of these cases, the demonstrators have the rough outline of the eventual production plane, but they may lack various features (weapons systems and hardpoints, stealth features, advanced cockpits, etc) because they just want to prove the concept first. Prototypes may often be smaller, carry less fuel, and be less refined than the final aircraft.
In contrast, other aircraft are built right off as production representative. They use the same production line and drawings, and the first aircraft built is (theoretically) identical to the production standard. In practice, there are usually some minor differences--the assembly process might not have been fully production-representative due to supplier issues (see 787 and A380), there might be minor internal differences due to lessons learned or late changes in the design, and internal furnishings like passenger seats are generally left out of the test aircraft. Sometimes (especially with military designs), specialized avionics like radars and weapons systems are left out of some of the test aircraft, and only fitted to the ones dedicated to testing those systems.
Obviously, all of these aircraft have flight test instrumentation fitted, and it is fairly common for the first couple production examples to be heavier than subsequent aircraft as detailed parts are redesigned to save weight. In the case of airliners, the test aircraft are often "cleaned up" after the test program is complete, and sold to customers at a discount to offset the airframe life used, and the higher weight.
I guess what I'm saying is that there's no reason to distrust one airplane over another simply because the first one was built right off to production standard, as long as it has been through a credible flight test program. In this case, where the issue seems to be LSA compliance, Van is using the prototype approach because he doesn't want to commit to a design without ensuring compliance. Zenith may have been more conservative with its design from the start, and felt confident enough to tool up and build it to production standards right off the bat. There's nothing wrong with either approach, and (IMO) as long as both aircraft demonstrate compliance during the manufacturer's test program, the approach used for the first aircraft should not be a factor in selecton.
