I love my wrist-mounted Gekko. Compared to diving with the console, it makes everything much easier for me. My SPG is still in the console, of course.
There are three pieces of information that you "need" on all dives: Remaining air (pressure), depth, and time. Of these, once you get a handle on your breathing rate, you'll develop an intuitive feel for your air consumption. This doesn't mean you don't check the SPG regularly, but for much of the dive, you're basically making sure it agrees with what you know it will say. (When nearing turn pressures, ascent pressures, or whatever, you'll quite likely want to watch it more closely.)
Time is not necessarily so intuitive for me. If I'm diving somewhat near the limits of my computer (which I consider acceptable, at least with a Gekko and the settings I select), I'll often need to keep close tabs on my time. Not having to look down for that makes it a lot easier for me. I'm horizontal when I dive, and I'm often just inches off a silt bottom in order to see the tiny things I'm checking out. If I were to have to look down (or sweep a retracted console up to look at, even), I'd have to ascend enough to not stir up the bottom.
When I'm not just off the bottom, depth becomes of primary importance. Diving along a vertical wall with no bottom for 140+ feet, it's a lot easier for me to keep my wrist in front of me for an absolute reference than it is to keep looking down at a console. The wall itself is a great short-term relative reference, but it's all too easy to slant shallower or deeper as you go along, and having to look away from the wall to watch your time and depth only compounds the issue. Also, when ascending and making unanchored deep, safety, or deco stops, having your depth (and time, too) on your wrist makes it much more straightforward to maintain constant depth. You could keep looking down to a console, but it's a lot easier for me to look at my wrist in front of me while simultaneously watching the floaties in the water (and noting whether there's any upward/downward drift to the floaties).
Now, certainly, it's possible to dive safely with either console or wrist gauges. I and my most experienced buddies have just *personally* found that there is an added convenience to wrist-mounted information when it comes to being (possibly excessively) vigilant in our diving. We dive horizontally, and having more information available in front of us in our direction of travel is appreciated.