For me big difference between the BD nForce and the Petzl Ascension ascenders is that with the nForce you can pull back on the cam release trigger with either the index finger or thumb of the grasping hand while with the nForce you can only pull back with your thumb, and I found this to involve more stretch and to be uncomfortable with the Ascension. The nForce has a longer cam (more contact area). The Ascension does have a slot up the center of the cam which is supposed to allow mud and ice to exit the contact area between the cam and the rope, but I have never used the Ascension so I don't know how well this works. Also, the nForce has shorter, straight (90-degree) teeth (over a larger area with what BD says is pressed against the rope with 30% more force, when under load, due to the the unique cam action.). The Ascension relies on teeth that are angled downward. Have not tried the nForce with gloves but they are roomier fit. I found the easier trigger action of the nForce to be my main deciding factor.

Used these a whole buch and they worked perfect

On one ascender I noticed the cam sticks and will not always lock down on the rope. It's especially bad when the dirt and dust gets into the pivot point. It's never been dropped and its only a few months old. I'm returning these to go with the petzl instead.

I picked these up to add to the gear and the climbing possibilities. Very happy I did! I do like these more than others because of the smooth operation. Even starting out at the end of the rope with a light pull of the "trigger" it glides up the rope nice and easy and locks solid. Have not tried with wet or icy ropes yet, but I would imagine the same performance. I paired mine up with the metolius easy aiders and wow what a perfect combo!

I bought a pair of these at the beginning of this season, put a few ascents under my belt with them. They do a great job and they handle the rope better after about 15' of height. They are easy on the rope, and are beefier than the alternative name brand. I never regretted buying them, and the chicks like em too.