Don't waste your money.
I haven't tried those particular lights, but have a pair of similar LED lights with (if I remember right) 24 leds all facing forward. NOT NEARLY BRIGHT ENOUGH to even pretend to be driving lights.
(wired to a connector with a 6 foot cord they make a reasonable trouble light though, and the current draw is low enough to not worry about them killing the battery if they are used with the bike not running)
On my 650 I tried to measure how much extra charging/output capacity I had by hooking up various combinations of resistors and bulbs etc. up at various RPMs and checking the voltage and current. I came to the conclusion that 2 amps at high idle, and somewhere around 4 to 6 amps at above 3500 rpm was about the max you could continuously load the system. Thats allows ONE 55 watt halogen (not a pair)
I have come to the conclusion that if you want more light, pretty much the only option for a GS is going to be using HID bulbs in the headlight.
(Real HID, not the "HID look bulbs" ... If it doesn't come with a ballast, it isn't a real HID system)
35 watt HID gives about 3 to 4 times as much light as a 55 watt halogen, and will actually use an amp or two less current, letting you use that current for something else.
Appropriate motorcycle HID systems are going for about $50-60 on E-bay right now, I haven't checked into other sources.
Start with this search string to see examples:
HID (Moto,bike,Motorbike,motorcycle) -bulb -bulbs -ballast -relay (hilow,"hi/low","bi-xenon",bi,by,dual)
The correct systems will say something about "Hi/Low" or "Bi-Xenon" or similar, indicating that they do both the High beam and Low beam from one bulb.
The fly in the ointment is that they are NOT DOT approved anywhere in the USA. They can only officially be sold for offroad use.
If you have state inspections they will not pass, and if a police officer wants, he can pull you over and cite you for it, possibly even impound the bike.
OTOH, if you don't get a "blue" looking bulb, I don't know how easily they could tell just from the extra brightness.
A second minor point against them is that they won't work with headlight modulators, which I think are a big plus visibility wise.
And finally, two additional points about headlight brightness.
1) The brightness of the stock system is HUGELY influenced by the voltage at the bulb. With the anemic wiring and a couple of switches dropping some voltage, its probably possible to get a noticeable increase in light output just by running direct dedicated 12 guage wires (switched by a pair of relays) to the headlight and eliminating some of the losses.
2) There are better 55 watt halogen bulbs available, for example the OSRAM Silverstar (NOT the Sylvania Silverstar ... If the bulb glass has a blueish tint, its the wrong one)
These have a filament that burns hotter, so they produce more light from the same input power. Its not that much extra though, only about 50% more.
The main disadvantage is they only last 1/10th as long or so.
However, they are DOT legal everywhere.