The whole -4 is so hard to build compared to a <insert later model here> thing is way overblown IMHO. Nothing is all that hard about building any of these planes. Sure the latest models are more pre-fabricated and largely pre-drilled but learning the very simple steps of laying out rivet lines, drilling holes, riveting, etc. IS NOT HARD. It is just time consuming. The "hard" parts - cowling, canopy, etc. are just as hard on the later models as the older ones.
The basic tradeoff is time versus money. You pay more for the later kits and more is done for you hence less opportunity (I didn't say no) to screw up.
The people who built all the 3s, 4s, and 6s (all similar in amount of prefabrication) were not and are not building superstars. We just put in a few more hours doing basic mundane tasks over and over again.
The commitment level to needed to see the thing through to completion is the "same" in my mind even if the total hours may be a bit more on the earlier kits.
This is my opinion obviously but a fairly strongly held one. Not everyone can afford or needs the features of the alter designs and I hate to see people possibly being scared off for now reason.