The net effect of any WD system is the transfer of weight to the tow vehicle is balanced by the same weight transfer to the trailer. In a trailer with a softer suspension, or already loaded up, this could take away what little travel there is left, giving you a harsh ride and beating the crap out of your trailer. Likewise, if you managed to really crank them up, you could put too much weight on the front axle of your 'Burban (that would be hard to do).
You need to start out with the hitch weight of your trailer and see if WD is even needed. With 3300lbs, you'll want somewhere between 330~500lbs on the hitch. Transferring weight might not be needed... especially when you factor in adding 150lbs of hitch to the equation. But, you are getting some sway control if you are using an actual e-quilzer brand rig.
I tow ~4500lbs tandem axle, ~500lbs on the tongue and found I was basically adding enough WD to offset the weight of the hitch. By using a short hitch, I have my ball as close to the axle as possible, which further reduces the need for WD. A lot of the more complicated WD setups introduce a lot of bad to counter... long draw bar lengths, heavy weights...
Anyway, just took off the remainder of my EQ hardware and am sticking to just my Airsafe after experimenting in some very high cross-wind with lots of big rig traffic. Us small-fries could do with just some good sway control... check out the new Andersen hitch which might be a simpler setup.