When we shopped for a new trailer, I considered the optional disc brake option. It was less expensive purchasing it then, instead of an upgrade later. The option included an electric/hydraulic actuator and as far as pricing, I can only remember that it was quite expensive. We have some hilly areas where we live, and while certainly not as precipitous as in the West, we had some concerns about the down hill braking capabilities with the larger trailers.

After asking countless questions of everyone who would listen, I decided that the standard electric brakes would suffice. If I needed additional hill holding, I planned on the addition of a future diesel engine braking devise.

It has not been a necessary option. While using the OEM equipment, I've always had enough brakes, no fading and excellent long term wear. My largest trailers were purchase used, and both have the standard electric brakes installed. I do not like or use surge brakes, which some of these newer components were intended to replace.

If your driving constantly includes long, mountainous down hills with a very heavy trailer, a disc brake option may be a serious consideration. The disc brakes would provide more of a fade free system.

I don't think I would find the optional electric/hydraulic DRUM brakes, worth the extra cost over the basic electrical actuation. For us, the standard electric actuators and brakes do an excellent job at nominal prices, and few maintenance issues.

Gard

Trailer Doctor.  It will depend some on what you are towing with and how heavy the trailer is, and what type of terrain you tow in. 

Hydrauilic brakes are more powerful, but as Gard pointed out, more expensive.

You didn't say how big your LQ is, but an 8' shortwall with 3 horses is probably 14,000 to 15,000 lbs loaded. And a good 1 ton truck should handle that with electric brakes. Now a 17' shortwall with double slides, 8' wide and 8 ' tall and three horses and all the extras a high end trailer has, is probably more like 20k loaded and hydraulics would probably be a strong option.

If you are pulling with a dually truck, you already have more braking than most trailer owners who are using a non-dually. On my 2000 F350 with the 7.3L engine I went through a lot of brakes because of the heat build up warping the rotors.  On my 2006 F350 with 6.0L engine, I have not wore out my brake rotors as often even though I am pulling bigger trailers.  The newer TorqueShift tranny has better engine braking than the my older Ford did. Also ford increased the Rotor size in 2005 to give mroe braking surface on the rotors. ( That is reason ford went to 18" rims in 2005 vs the 16" rims they used previously). I set the cruise and the engine holds me all the way down the hill and I rarely have to use my brakes on long downhill grades.

So what truck you use to tow with, should influence your choices.

My last trailer had Hydraulic brakes on it. It was a home made trailer (4H) and was fitted with ventelated discs on all 4 wheels..... the brakes were superb. We use our trailer in some mountanous areas and I can quite easily say that they are far superior to the magnetic standard units....

If you can afford them now - I would go for it. You will not be sorry.

Mine was fitted with a shut off valve just after the actuator - this meant that you could manually actuate the brakes, shut the valve off and whalla - you have a hand brake. (Not that that is esential - but I did use it on the odd occation.

I really liked my Hydraulic brakes - and my next trailer will definately have them fitted.... without a doubt.

Good luck