I received my new pair of Cobras last week and got to take them for a spin along with my buddies Viper tools, both with Android leashes. FWIW, my previous daily driver was the old Cobra and before that was the CFBP's (which I still use for alpine mixed).
First, let me just touch base on the question of durability of the carbon fiber. My CFBP's have had the crap beat out of them. Scratched to hell, pounded on, smacked around and still going strong after 10 plus years. My old Cobra's were used for about 7 years or so and also, no issues. BD did a strength test a while back on tools and when smacking them on the curb, the CF tools lasted longer than the aluminum which would eventually buckle and break. My point is, I personally trust the strength and longterm durability of Carbon Fiber tools.
The new Cobra's came out of the box absolutely beautiful. They are a work of art, and that was the reason that I was willing to pay the extra money. Personally I am just a huge fan of carbon fiber--always have been--and with the past two pairs of CF tools, I did not even really consider not getting them assuming that they performed (which they do). The epoxy coating on the tools is easily scratched/chipped--oh well, they all start out beautiful. I hope that it will remain just superficial scratching like the other Cobra's had--I have no reason to suspect anything different, but these come from China which may or may not mean a damn thing. We will see. The construction quality and appearance of materials is outstanding.
I really like the grip--still has that oval type shape but only very slightly hour-glassed compared to the old cobra's. I like the grip shape better and it is still on the smaller end of the scale which I also prefer. The grip is flush molded in and has a rather nice almost sticky texture--very easy to grip--along with ridges that really allow you to grip the tool when leashless. The Fang and the Strike were both sized well, in my opinion. If you do not want the Strike, BD provides a little plastic screw that will go into the hole when you take it out--there is a threaded insert that is molded into the tool under the strike.
The hammer and adze are tiny--almost too small to use. I have two hammers plus a spare adze just in case--sometimes the adzes are easier to drytool with in big cracks, so it can be handy. Pretty useless for pounding pins or chopping steps, but you can in a pinch.
The Viper is also incredibly well made. It uses a very similar grip but seems slightly less textured and not quite as "high end"--you will have to compare them side by side to see what I mean, but it is a small detail which sort of helps justify the Cobras (but only very slightly). Shape wise in the hand, it felt remarkably similar to the Cobras. All the options for Fang/Strike/Android are identical between the tools and when using one tool in each hand, even the android leashes seemed to be in the same place.
The Cobra tool has a different weight distribution than the previous version. It seems that the shaft is even lighter and this leverages the weight/balance of the tool to it's head. If you hold the tool straight up and down, it feels very light, but when you hold it horizontally or try and do mini swings, you will notice that almost all the weight is at the head which makes you adjust your swing style more. I found that I could swing softer and the head would transfer more energy from the tool to the pick and it would place easier (or deeper). This I found true for both the Cobra and the Viper. Compared to the old style Cobra, which I think are amazing tools, the biggest difference is in this swing weight distribution and added shaft clearance. A lot more. You can hook like made with these tools--the clearance makes it really easy.
I did not notice a problem on low angle ice--probably because I am a wrist flicker as opposed to an arm swinger, but they performed fine. This is a tool that really likes a little wrist flick, IMHO. If you want to drive it in, though, it will go.
Performance wise, I am very, very happy and would recommend either of these tools strongly.
When climbing with one Viper and one Cobra tool in each hand, the weight and grip were similar enough to be able to forget which tool was in which hand. When swinging onto ice, it seems that the pick angles are identical and again, you could not really pick out which one was which. As a matter of fact, the only real difference that I was able to discern between the tools was that the when you hang on the Viper and pull down with body weight, the shaft flexes a little bit and the Cobra has no flex at all. The ice was rather soft when we were out, so I can not tell how this difference will make the tools compare in brittle ice, but my guess is that you may be able to tell a bit more of a difference on bulletproof ice--what that difference will be, though, is just a guess. My guess is that stiff shaft and slightly higher head weight of the cobra will make it penetrate a little better by transferring the energy to the pick, but I doubt it will matter much.
Comparing the profiles of the tools, you will notice that they are very, very similar with the Cobra having maybe 1/4" more clearance at the bend in the shaft--the pick angle and handles align very closely, enough so to think they are identical.
The tools take the standard BD Pick. My Aermet picks (I still have a few) and older picks all fit just fine--THANKS BD FOR NOT CHANGING YOUR PICK ATTACHMENTS!
So, in summary, I think both tools are top notch and would highly recommend them. From past durability experience, I would say that both tools will also perform long term and I would not chose one over the other from this stand point. The Cobra is stiffer and has a nicer grip (slightly) and seems to have just a little more weight leveraged to the head as opposed to the shaft. My guess is that it may perform a little better on harder ice, but that is JUST A GUESS based on thinking it will transfer more energy directly to the pick. Actually, I would consider either tool and the answer would boil down to money, with the Cobra tipping the scales by another $150/pair ish. If I was strapped for cash, I would not hesitate to get a pair of the Vipers at all.
I was also asked my opinion of the new Cobra versus the Quark--I think the Quark is an awesome tool and I would definitely consider the Quark when considering new tools--both have a different swing with the Cobra having its weight leveraged at its head and the Quark appearing to be a little more balanced down a little lower on the shaft. My leaning to BD is due to the way their picks attach/remove, the quality of their picks, and, quite frankly, that I have a certain brand loyalty to BD when it comes to ice tools (and about 10 extra picks from over the years). The Quark is an amazing tool IMHO.