My opinion is that the #4 V3, which is the only one I have used, is very well made in every aspect. I think it is an absolute bargain and works perfectly. Smooth, predictable operation, nicely finished, comfortable. I also have the polar opposite. A modern Stanley #4 "contractor model" purchased about 10 years ago. Despite many hours of fettling, it is barely fit to do the roughest work and incapable of smoothing. The operation is best described as stiff and crunchy, unpredictable and uncomfortable. It is made in the general shape of a Stanley Bailey #4 but that's where the similarities end. Both planes are made offshore (Both in China, I believe).
If I were to purchase another modern bench plane, it would be a Wood River. But it's doubtful I would buy one at all.
The vintage planes have 3 advantages for me over any modern plane. First, they are much less expensive. The several vintage planes I've purchased have required very little effort to prepare. The most expensive of the lot was still a small fraction the cost of a LN, Veritas or even Wood River. Secondly, they are significantly lighter that the modern premium copies. I much prefer lighter planes. Lastly, I like using (reusing) the vintage tools. I like the history and patina, I like that they are being used to make things instead of going to a landfill or being turned into a coat rack. As a bonus, I think the vintage tools are possibly superior in some ways. Many will disagree, but I'm not convinced the new irons and chip breakers are as good as the old. The different shapes, thicknesses and alloys are just that: different. Perhaps hundreds of years of experience in working wood influenced the way the old plane were designed but no one bothered to write it down for today's engineers to read.
Maybe they did write it down but we think we know better today
If I ever buy a new plane, I'm pretty sure it will be a wooden double iron plane.
-- Dan Rode
"We are what we repeatedly do. Excellence, then, is not an act, but a habit." - Aristotle