Tact,
I've seen this subject kicked around so much on every forum and have found the concensus. The answer is... there is no concensus. There are thoughts, recommendations, considerations... but I believe it came down to personal preference/need and $. If you have the full cab, plow... you probably do need it. For those of us with slightly less, it comes down to need. Try it without. If your front end sags, tires rub or whatever, then go for it.
Here's a test (if you haven't mounted the cab and stuff yet)
Get a measurement from the floor to a reference point above the suspension in the front (like the bottom of the front receiver). Get an estimate of the weight (or just take all the boxes full of stuff you're about to mount and set them on the hood or something). With that weight now onboard, re-measure. Once done, tell us your findings. Depending on your terrain, tires... (how much suspension travel you may encounter) that may determine whether you will have an issue. My guess would be if you loose about 3/4" or less, you'll be fine.
Myself, as previously mentioned, I've added a bunch of stuff to my RTV. Probably in the ballpark of 3-400# worth. I also put on taller tires which made me loose 3/4" inside the wheel well. There is only 1 condition where I can get just a little rub. Put 12-1300# of logs in the box and come down a steep trail into a hard left turn at a decent pace (now there's significant weight on the front right tire). I get just a little rub.
As for a discussion on this, try
this thread
Brian