The problem with heavy bows is not actually a problem with the bows, it's the shooter. Seems to me a lot of people just shoot heavy bows so they can beat their chest about it, and don't give the bow the respect it deserves. All other things being equal, and heavy bow is definitely better than a light bow when hunting, but I feel like most people don't devote the proper time to build up their strength and form to be able to shoot heavy bows correctly. If you are straining AT ALL, or getting tired after a few minutes of shooting, you are probably overbowed. I know this because the first custom bow I bought was a 70# one I bought when I was young and dumb. I didn't do anything to work into it, just picked it up and started flinging arrows. I was young enough that I didn't hurt myself, but my shooting sucked and didn't improve until I dropped weight.
People say it all the time, but it seems like a lot of shooters still don't get it; the best draw weight is the ACCURATE one. If that is 30# for you, don't worry about it, shoot that and work up very slowly if you feel you must. You'll shoot better, and your joints will thank you.