I'm usually someone who likes black. Black bar tape, black saddles, black bikes etc. I was in such a shock when I received a set of gold cables for review that I forgot to weigh them (sorry, but jokes aside I need to source a new set of scales before I can post weights). Since I won't be able to post weights, this review will mostly entail the installation and use. If you are interested in the weight, Art's Cyclery cite a weight of 115g for the (complete) shift kit and 118g for the brake kit. Considering how much housing is supplied, these weights seem reasonable, and are comparable to BDOP's kit. After cutting, I would suspect that these cables will come in at a similar weight to BDOP's kit (if not lighter).
First things first, these kits aren't compatible with full length housing, since the cables rely on splits in the housing to facilitate easy length alterations (unlike traditional housings which can just be cut to length). Having said that, there have been a few documented cases of this kit working with full length rear brake systems (see Krackor's post). Jagwire do supply plenty of the inner housing, if you've got a frame with split internal cable routing, you should be able to make it a fair way into the frames with this inner, which should help in keeping the cables sealed against the elements.
While Jagwire sell this as a 'link' system, these are quite different to other link systems on the market. They feature a pre-lubed inner housing, which the links 'sit' over in a head to toe fashion. Jagwire use a standard cable housing under the bartape, which connects to the inner housing either via a barrel adjustor, or a special link (both supplied). I'm guessing Jagwire do this to make internal handlebars slightly easier to install, and to avoid super tight bends with the link section.
Installation was actually surprisingly pain free, but not as easy as traditional cables. You first need to cut the section which goes under the bartape to length, and tape it in place. This wasn't too much of an issue, but be careful to check if you've got the shift or brake housing as they look similar but are very different (they come labelled).
Once you have the bartape section done, you'll then need to attach the rest of the housing to it. This can be done either with a barrel adjuster, or a special link. If you're planing on using the barrel adjustors, Jagwire's approach to this isn't ideal. If you follow their instructions you'll end up covering the barrel adjustors with your bartape, as illustrated in the photos below.
You can avoid this by running the bartape section housing longer (so it extends past the bartape) but this isn't ideal aesthetically. For this reason I would suggest you avoid the barrel adjustor. The special link they supply sits much nicer under the bartape and provides a smoother transition from regular housing to link housing.
In terms of judging housing length, if you cut the inner housing cautiously this kit is actually quite forgiving, in that you can insert/remove links over the inner housing. When I installed this kit, I left the inner housing slightly too long so it extended past my cable stop, which is aesthetically not ideal, but means I can add links if I accidentally removed too many (which I have a tendency to do). The weight of the inner housing is pretty negligible, so I would rather be safe than sorry when cutting.
Out on the road the shifting was smooth, rivalling that of the polymer coated cables from Shimano. Compared to the cables found as original equipment of lower-mid range bikes these are definitely an upgrade, undoubtedly a level above the cheaper options from Jagwire. Even with the tight bend created by my 36cm handlebars I still experienced slick shifting, with no hint of cable friction.
The black coating on the cables no doubt aims to reduce friction, but can also improve the cosmetics of certain externally routed frames. Most frames these days have internal cable routing, so this is a moot point. However, for those who prefer externally routed cables, the black coating does help the cables 'blend' in more.
Jagwire supply some rubber frame protectors you can slide over the links. Shrink wrap is a lighter alternative, but it's nice to see details like this included in the kit. Also supplied are some clips to clip different sections of housing together, making it easier to achieve a clean look. I found the hardest part of making the cabling look 'clean' was finding the optimum length, I couldn't decide if I needed that extra link or not. In the end I decided to include it, though it'll probably look cleaner without it.
The compressionless housing also helps in obtaining a tidy front end, you can shape the housings a lot more than with traditional outers. Having said that, the housings do shift around a fair bit, which is probably why Jagwire supply clips to help keep them from moving too much.
Apart from gold (and black), the housings are also available in silver red and blue allowing some customisation. I'd say all of the coloured options (red, blue, gold) are quite eye catching, and would look great on a suitable bike.
If you're in the market for a lighter alternative these are certainly worth looking into. They're no harder to install than traditional cable housings and certainly perform just as well as the stock Shimano cables. PowerCordz, and other designs will be lighter, but possibly more hassle. I would consider these cables to represent a nice compromise between outright weight and ease of installation. Perfect for those who are a little intimidated by more complicated systems, or simply want an easier system to install.
To conclude, these cables represent a nice aftermarket customisation for your bike, and are a significant upgrade over lower end cables. If you like the looks and weight reduction offered by link housing systems these are definitely worth considering, particularly if you're intimidated by the complexity of other systems. Most Weightweenies are probably happy to spend a little extra time fitting lighter systems (or have a mechanic do it for them), so this is more of a 'middle ground' giving some benefits of compressionless link housing, while retaining the simplicity of traditional housing.