In my last batch of updates (back in March), I mentioned that I was waiting for an order of strings (along with other things, which will get their own post). That order arrived about a week later, but I haven't had time to write my review on them before now. For the sake of clarity, the strings I ordered:
Ernie Ball Earthwood Acoustic Medium Light (0.12-0.54)
Ernie Ball Cobale Electric Slinky (0.10-0.46)
I used these to replace my Ernie Ball Coated Acoustic Light (0.11-0.52) and Coated Titanium Regular Slinky (0.10-0.46) strings on my acoustic guitar (an Epiphone Artist Series EJ-200), and my electric (and Epiphone Les Paul Tribute '60).
The first thing I noticed when using these strings for the first time was the strong textured feel of the strings (compared to the coated ones I was using before). I actually think these are a little "rougher" feeling than other normal strings I've played - which is by no means negative. Once I got to strumming the strings, I was blown away by the bright sound of the bronze. Combined with the jumbo size of my acoustic, it led to quite a powerful sound. Even though the strings (and guitar) can be loud when played forcefully, they keep their definition of tone. Also, playing softly results in a perfect volume for intimate acoustic performances, or for practicing in a room without bothering anyone else. I find that the .12's are still very bendable on the jumbo, and I don't think I'll be using any other gauge on this guitar in the future.
I've experimented a little with recording this setup too, and the sound can be picked up extremely well from various positions. The microphones I was using didn't manage to cope with the low-ends of the jumbo, so I won't post any sound samples, but I highly recommend these strings if you have a jumbo (the smaller gauges will probably have a similar effect on any dreadnought or folk guitar you try them on).
Besides tone, of course, is the question of durability and price. The coated strings I was using earlier lasted very well, but were about double the price of the Earthwood strings. I estimate that the coated strings lasted me about 4 months (I admit, I failed to mark the date on the pack, which I usually do). So far the Earthwoods have been on my acoustic for a little over 2 months, and, while looking a little worn, still sound extremely pleasing to my ear. I don't think I'll need to swap these strings out for another few weeks, possibly as late as the first week of July. And yes, I have played the guitar a lot since putting them on. I tend to play between 1 and 4 hours of guitar a day (depending on factors like other work I need to do). Also, since my preferred playing style is fingerstyle guitar, the strings have been in contact with fair amounts of corrosive oils from my hands. The weather has also been rather hot, putting further wear and tear on the strings. If the muted color of the bronze doesn't bother you, you'll be more than capable of using them for extended periods of time. The price, at the time of writing, is 6,90€ = £5.57 = $8.67 at Thomann.de.
Electric (Tribute '60)
The first thing you notice about these strings, even before you put them on the guitar, is the dark color of the metal. I actually find that it looks quite nice, though I have to admit that the guy at the guitar shop asked me if I had ever changed the strings since buying the guitar (I had to take it in to get adjusted, since I just wasn't able to find settings I liked). If that doesn't bother you, then I think you'll be extremely happy with these strings. Played on clean settings, these strings offer better tone definition (it's hard to describe exactly what I mean with this - I think the best description is that, regardless of what you're playing over, you'll be able to distinguish the notes fairly well). I also find that the pickups on my guitar tend to have better output (since iron and cobalt are both ferromagnetic materials). Ferromagnetic materials are simply materials that can form permanent magnets, or refers to metals that are attracted to magnets. Since cobalt and iron attract the magnets in the pickups more than titanium, steel, or nickel, it results in a more accurate translation of string vibrations into the amp via the pickups. True to the name, the Regular Slinky pack is, well, slinky. Bends are easy on the fingers, and the higher tensile strength of cobalt reduces string breakage. As for how they feel. I don't find they feel any different than any normal strings I've ever played on an electric. They do, however, feel a lot more like normal strings than coated strings do (even Ernie Ball coated strings, which are the closest facsimile to non-coated strings I've found).
Due to the high corrosion resistance of the cobalt, these strings should last you a fairly long time (also why Ernie Ball doesn't offer them coated). I'd be hard-pressed to say the strings look any different than when I first put them on the guitar (about 2 months ago). It's also possible that I can simply not see the difference, due to the darkness of the cobalt itself. In any case, the strings sound just as good as they did before. I admit, I don't play my electric nearly as much as my acoustic, but it has still seen a fair amount of use. As for price: These strings were a bit cheaper than the coated strings I was using, but not by much. These days, I think they're priced about the same. In any case, I find the quality of these a little better than the coated strings, so it's a price I'm more than happy to pay. (at the time of writing, it's 10,90€ = £8.79 = $13.70 from Thomann.de)
If you play guitar, and you want a nice and bright acoustic sound, I highly recommend giving the Earthwood strings a shot. I certainly wasn't disappointed, and these strings sound great when flatpicked or fingerpicked.
Similarly, if you play an electric, especially with coated strings, consider trying a package of cobalt strings. The price is the same as the coated strings, but I find these a bit better than the coated strings (with hardly any trade-off on durability).