I could be mistaken because I didn't record the numbers. But if the bundt wheels are that light, then it doesn't make sense to pay the recently advertised $400 per rim for the pressed aluminum just for the weight advantage.
My opinion is that you buy the wheels that you like the appearance of first, and if you can get it to weigh a lot less, then it is worth it. I have the pressed aluminum with full wheel covers on my 1971 250 C and on my 1985 300 TD. However on my 1967 250 SL I have the steel wheels with the dog dish hubcaps and the trim rings because I like that look better than the full wheel covers. Sidenote: the $400 is the ebay price, I regularly sell the wheels for $300 on the forum. (6" version, not 5.5" version). I have never actually sold any at the $400 ebay price.
I don't think anyone is going to switch from full-wheel-cover steel to bundt just for the weight savings. They would be far better off with the pressed aluminum and full wheel covers. Even the 5 1/2" pressed aluminum would be just fine.