The big difference between the 3200 and 4200 is that the 4200 is fully multi-coated, and gives the extra light transmission. All the Elite line are made by LOW in Japan, who made the Bausch & Lomb line before Bushnell took over. They also make Weaver, and other quality scopes including some high end ones that are way over priced. While Leupold assembles scopes in the USA, they don't make the components there. Quite likely some of Leupold parts come from LOW as well.
This said, there are fairly limited times your eye can make use of the extra light transmission. If you take a 3-9x40 scope, it produces about 40/9 or a 4.3 mm exit pupil. While even an older person can use that much exit pupil, in normal light, your eye closes down much smaller and the extra light is of no value. 91% vs 95% just means it closes down about 4% less, and your eye sees the same brightness. In other words it makes up for the glass. The extreme is putting on sun glasses. Light transmission is significantly reduced, but your eye opens up and compensates so you still see fine in daylight.
The only time it is going to make a difference is when the light gets so dim that your eye is fully opened up to 4.3 mm and is using all the light it can get, which is possible before and after sunrise. But 4% is quite small.
The rumor on one forum in the US is that Bushnell is discontinuing the 3200 and 4200 series, and merging them. If true I expect they will likely all be fully multi-coated. There are reports of close out sales. You may want to wait a bit, to see if that happens here, and if you can get a bargain on a 4200. See this link:
Midway USA Bushnell Elite