First of all, definitely check this out: Carbon Fiber Trekking Poles Review Summary and Gear Guide Overview
Personally, I typically use trekking poles full time and don't mind strapping full-length poles to my pack (except for off-trail in brush, but I tend to gravitate to sub alpine or desert environments where this isn't an issue). As the trekking pole guy at BPL, I'm spoiled and have used almost every lightweight pole on the market. I love the BMW Stix (the best but very expensive), the Gossamer Gear Lightrek (very light and with a comfortable flex- I find they're strong and stiff enough for all but the heaviest hikers), and the Komperdell Featherlight (super stiff and strong). For trips where I need collapsible poles, I use Komperdell C2 poles. They're strong and have a Flicklock-style locking system, but at a MUCH lighter weight. Some people have had bad luck with the Komperdell C3 but I have a pair that I've been really hard on and I've had no issues at all. My experience has been good, but I do prefer the simplicity of the C2.
A pole that we hope to have in soon for testing are the Titanium Goat Adjustable Goat poles. We had good luck with the old Ti Goat poles and this new model addresses all of our previous concerns AND they're adjustable. They hold a lot of promise- I can't wait to use them!
Poles are certainly a preference issue but here are some cold hard facts: At the same weight, carbon poles are much stiffer than aluminum poles. A few extra ounces in your hands may not seem like much but when you lift them thousands of times in a day, the weight really adds up- like lightweight footwear, light poles make a much bigger difference than pack weight. Lightweight poles make for quicker placements. The most reliable mechanisms are no mechanisms at all- fixed length. Straps are a preference thing but they definitely add to pole weight and many people never miss the straps.
Last, I'm an over-agressive pole user which makes me a good pole reviewer because I often test them to failure. I've broken more aluminum poles than carbon poles, despite the fact that I haven't used an aluminum pole in several years. My opinion is that carbon fiber is an excellent choice for a lightweight hiking pole.
Besides that, my old 8 oz poles seem so clunky- I can't hardly stand using them. Going to light poles is like switching to an UL pack weight or trading the leather hiking boots in for lightweight runners. Once you make the trade, I doubt you'll ever go back.
Best of luck in your search!