Among some of my friends getting into cycling/triathlon, probably the most common question I get is how they can get faster. That one is easy. You need to train and get your engine to go faster. Outside of simply getting more fit, it is possible to "buy" speed on the bike. Along these lines, my number one response on where to put your money is a formal bike fitting at your local bike shop. If you aren't comfortable on your bike and positioned in a way to maximize power transfer, you aren't being as efficient as you can be. Comfort can be extended to other things such as clothing, bike saddle type, and specific to this upgrade, arm bracket cushions.
For triathletes who spend the majority of their time in the aero position with your forearms resting on the aerobar arm brackets, the pads your forearms rest on better be pretty damn comfortable. They should absorb the bumps from the road well and keep your forearms from aching during the longer rides. I remember the days when my long rides would slow down toward the end because I'm constantly shifting my forearms to be comfortable on the arm brackets or even going upright on the bull horns to give my forearms a rest. Both of these scenarios aren't going to help your overall speed.
One of my upgrades this season was getting rid of the crappy stock pads that came with my aerobars and trying out Ceegees Cushys. I heard great things about these pads on the forum sites and decided to buy them and see if the product was worth the praise.
Cost-wise, they generally run about $30 for a pair. Gut-reaction is that it seems pricey for two pieces of foam but considering the comfort factor and spreading the cost out over two seasons (which is how long I expect the cushions to last), the price seems fairly reasonable. On the website, they seem to have every popular brand covered so selection shouldn't be a problem. From my experience, their customer service is pretty responsive so I'm sure if you had something outside of the box, they can make a recommendation on what might work best.
When the Cushys arrived, I noticed that they looked a lot more robust than the stock arm pads I was using. Best way to describe it is that it is a two layer foam. One layer with foam similar to the stock arm pads and another layer of foam that looks like something from a beer koozie.
The Cushy's pad was cut to fit exactly like the old stock pad and installed in seconds. Since then, I've taken them on a few 70+ mile rides across different quality levels of road/asphalt. The pads have also held up fine with no signs of wear yet so they seem pretty well made. I will say that I cannot remember one instance of thinking to myself my forearms were achy or uncomfortable. Actually, I don't even think about it at all which is a good thing, though I'm sure if I had to go back to stock pads, I could immediately feel the difference after being pampered with the Cushys. Overall, I give the Cushy's a thumbs up and recommend upgrading to these pads, especially for longer bike rides.