I write about what I use, and I buy what I use. No freebies or sponsorship. Other gear might work as well or better for you.
In 2005 I was climbing unroped with a 40 lb. load, heading for Camp 1 on Broad Peak. After climbing a couple of 40 degree sections of water ice, I was glad to set foot on snow again. At that precise moment, I felt something rattle on my one foot. I looked down and saw that one crampon had fallen apart, the two pieces dangling from the straps. A nearby climber gave me a hand and it was soon fixed. The problem? The quick release mechanism (which adjusted the length) popped open when used on my very big high altitude boots. If this had happened 20 feet lower on the water ice… That’s when I got serious about building a boot/crampon system that was bombproof yet light and precise.
On both K2 and Everest I used a two boot/ two crampon system. At lower altitudes, the Trango boot and Petzl Sarken crampons were a nice combination of warmth, durability, and technical agility. I must admit that on Everest I actually used M10 crampons as my previous Sarkens had been recalled. Petzl anti-balling plates are far superior to the Charlet plates on the M10s. The vertical front points on the Sarkens climb ice as well as a technical crampons, at least when using both the heel bail and toe bail binding. I would have used the Sarkens up to Camp 3 on K2 with warmer boots.
Once above 6700m the Trango boots simply aren’t warm enough and I switch into my La Sportiva Olympus Mons boots. I’ve used both these boots and the Millet Everest boots and prefer the Olympus Mons. They fit my feet better (the most important consideration), they are not nearly as bulky, and they allow me to do more technical climbing. Both crampons mentioned above fit these boots though you may have to whittle the heels down a little bit if you use a lever style heel bail. The lacing system on the Olympus Mons is unique but functions quite well as long as you don’t try to figure it out at 7500m. The outsole is quite fragile (in an effort to save weight). If you travel on rocks you’ll chew it up quite quickly.
The Camp XLC Nanotech crampons are aluminum with steel reinforcement under the front points. They are amazingly light and about as durable as you would expect for such a soft metal. They worked well on the Olympus Mons and I wore them from Camp 2 to the summit and back on Mount Everest, and from ABC to C2 and back on K2. They wear down very quickly if you have to expose them to rock; they would probably make one round-trip on K2. Of course weight is the primary issue and saving a pound on your feet is worth the price in this case. But you couldn’t use them as your everyday crampons in an expedition situation. 
For a single ascent without much technical climbing they will do just fine.
Retailers are quite happy to sell you way too much boot, pricewise. Know the worst condition you can reasonably expect to encounter and buy appropriately. If you’re stomping up Aconcagua or an easy trekking peak, a pair of plastic double boots are generally sufficient (and half the price of the specialized high altitude boots).
Make sure your crampons fit your boots! This may seem a no-brainer, but there are a lot of folks who don’t discover this problem until it’s too late. You may have to trim the boot heel a bit. The type of strap/bail system use use will depend on the boots and crampons you have, as well as personal preference.
Finally, make sure you have the tools needed to adjust your crampons, as well as replacement bolts etc. On Broad Peak I removed the quick-release clamps and bolted the suckers together. No more crampon disintegration.