4200 is the top of the line Bushnell scope, it is multicoated on all lens, states 95% light transmission so brighter, clearer than the 3200. It is tested to 10000 blow from 375HH. Cost about 200 bucks more. The 3200, is exterior lens multicoated, in the 90% range for light transmission and tested to 1000 blow from a 375HH. About 200 less.

Since I have both I can tell you their is a difference between the 4200 and the 3200 in brightness. My 4200 tracks true, where my 3200 doesn't always do so. Other than the price not much else, you'll notice. Eye relief is the same, both one piece tubes, both have raingaurd now, both have a wide variety of objectives and power selections. Honestly I would opt for the 3200. If I was looking at the 4200 I would buy, burris, leupold, nikon monarch, zeiss conquest to name a few. The 4200 is nice, but I would opt for some of the higher end scopes in that range.

I bought my 4200 at a sale, so it cost me the same as 3200 regular price then. I now use the 4200 on my ML, which is overkill, but got to use it, the wife might ask questions...hehe.