I think for racing a spot/euro pattern would be preferred.
I've got a euro pattern 50W HID on my LTR and it's F-bombing sweet for high-speed desert and road racing, it's almost a perfect pattern.
Good throw, the sides of the road are well-lit but don't take away from the center, very little spill-over to the sides, they don't blind oncoming traffic (the beam looks pencil-thin, which can make it a little difficult to adjust perfectly), and it's almost like you're running a fog light when it gets dusty (virtually no glare).
In fact, the throw is good enough that I'm comfortable at WOT in high gear with the LTR, I know that I'll have time to stop or avoid whatever is illuminated in front of me.

Any kind of duning or trail riding at night would definitely benefit from a flood only beam.
I've found that the euro pattern and spot pattern are lacking on the dunes and the more technical areas (climbs, sharp turns, etc.)
Here's why:
You're looking all around you at night, and with a spot beam your eyes are adjusted to the high intensity spot directly in front of you...so you can't see anything other than that spot.
If you're in a turn carving the side of a hill with the quad pointed up a little, you're not going to see what's at the bottom of the hill where you're headed until you can get that small, intense spot swung around to it.
Going up a dune, that spot is illuminating the crap out of the air and you could probably spot airliners going by, but directly below you is complete darkness.
Going down, you can clearly see exactly where the bottom of the bowl is at, but the next dune you're about to climb is complete blackness...and that means you have no idea how much speed to carry or if there's something near the top you need to watch out for (like a razorback, witch's eye, dumbazz parked up there without lights) until you've already started your climb.
A flood light distributes an even pattern all around you, side to side and top to bottom, so you have situational awareness because your eyes aren't adjusted to a high intensity beam in just one spot.
It's like going outside on a full moon...not much light at first, but when your eyes get used to the light you swear the sun's still out.
While the moon is still shining, take a Maglite and focus a pinpoint beam way out somewhere...you can clearly see something the size of a bucket 100 yards away, but you can't see anything around it, and you probably can't see your own hand in front of your face now unless you shine the light on it.
If you NEED to see farther than what the flood lights you have are capable of, don't go out and mix a spot light with the flood...that defeats the purpose.
Instead, you need to increase the flood light's lumens or buy another set/bar/whatever.
Increase the overall flood lumens until it'll project far enough for you to see what you need to.