I went hunting in Illinois (not far from Chicago) a good dozen or so times with my 44 lb hickory pyramid bow 68" NTN. Not the best made, 1.5 inches of set (better than the 3" of set on my first bow!). Average humidity over the season (Oct-Dec) was 60% plus on most of our trips. One day, we sat for a good 14 hours in a steady light rain. I wanted to stay as natural as I could with my first few bows, so I used that orange oil/ beeswax stuff--4 coats of it (I heated the bottle up in boiling water first). I did notice some cast difference after the 14 hour rain session. When I drew, it felt much easier--maybe even as much as 5-8 pounds easier. So I shot a few arrows while in the field and the arrow dropped significantly after about 15 yards--much more than usual. I packed it up fearing I lost more cast (dropping below the 40 draw minimum in Illinois).
When I got home, I steel wooled the bow, then left it on my floor heater for 6 days (before next week's hunt), resealed it again with 3 coats of that beexwax stuff and got 44 lbs out of it (this time I measured). It shot back to normal too.
I have no experience with other woods. I definitely noticed cast loss after a long day of sitting in the rain. I always hunted straight from 5 am till sundown every time we went. I guess I am saying that I like using the beeswax stuff becuase it doesn't smell bad and is easy to use/ inexpensive--non-toxic at risk of it not working as well as other finishes (in terms of keeping the water out). But I beat up that bow pretty good--staying strung for anywhere from 9-14 hours everytime we hunted and I only lost some cast after 14 hours in a steady light rain...
I don't mind steel wooling it up, then letting it dry over the heater...felt like I got to know my gear better, as weird as that sounds.
We'll see, though,how Chicago area's humid as heck summers treat it...I am not going to be able to throw it over a heater then...
Cheers,
Brian