Henchamp, with tongue firmly planted in cheek, between this post and the one in the Zeiss subgroup, you are revealing early symptoms of gearheadedness. An affliction, I and others struggle with as recovering gearheads.. Welcome to Birdforum.
Re the question you pose. Its a tough one to answer. I own EL1042 and NL832s. So there are differences in my experience from the one you might experience.
With regard to this, "What am I giving up going to the NL32...?" The only serious thing you will give up is cash. Seriously. They are both really good binoculars.
Regards NL rubber failing. This is a complaint that has been levied against the EL as well, for longer than the NL. I'd bet a dollar there is no chemical difference in the armor covering between either. My 3 year old ELs used a lot but perhaps not in such difficult terrain as some experience, look fine. Swaro takes care of it at no cost. Not much of a thing.
Re magnification bino makers label 8x42, 8x32, 10x40, whatever. Its important to understand that first number, the X is "nominal" that is its more than likely the actual magnification is not exactly 8 or 10. The EL 8.5 is sorta unique and promises to me at least an advantage over an 8, but what is its actual magnification? 8.4? 8.6? I shopped the NL 832 against SF832s. Both I and a dealer at one shop acknowledged the NL 8 view was higher X than the SF 8. Gils and John Roberts, (I believe) have written to this point. So dont buy the EL8.5 just cuz its labeled 8.5.
I find eye positioning on my NLs trickier than my ELs. I see glare in my NLs and never saw it in the 1042ELs. It is more a thing of conversation here on Birdforum. I was pissed to see glare at all in the NL after reading about it so much. But then took the advice from a couple people I respect and birded exclusively with the NL for almost 3 months. Glare was not an issue. It is a non issue.
I love the wasp waist of NL for a couple reasons. Many dont.
This may be more relevant. I bought the 832s as a compliment to a scope. The weight AND more importantly size of the EL42s was a bit of a problem hauling around scope and tripod. Not so much that they got in the way, but that they were in danger of banging into each other. The 832 is a happier combo with the scope. 8X is plenty with a scope in tow. The wasp waist facilitates one handed bino use with scope and tripod on other shoulder.
The NL confirmed how good the optical quality of my Els truly is. The AFOV of the NL is nice and helps with the lesser mag... Thats a much longer conversation though.
If I could have just one? Prolly take the EL 1042. Your 8.5 to me is a trickier choice vis a vis the EL/NL debate