depends on what you are after. If you want great top/bottom extension, sparkly treble, analytic and wide soundstage, then 1plus2 is your best choice
I didnt spend too much time with the K10 today, i would have a much thorough impression if i can home loan the unit. I demo'ed the K10 with the Ak120 for total about 10-15 mins. Below is what i can remember abt the sound with the stock cable
It has a neutral'ish sound, slightly warm. Treble is ok, no sibilance, but i didnt feel the sparkly sensation. The K10 definitely is not lacking bass, it is certainly there in terms of the quantity, but qualitative-wise, it does not bleed into mids, but in terms of the depth, control and responsiveness, it is lacking.
The mids blends in nicely with both ends of the spectrum, not positioned/projected to far back nor front. The detailing seems to be there with reasonable layering. Overall the sound stage is moderate, kind of in a vertical oval shape, whereas the 1plus2 is a horizontal oval (with stock gold cable), and the mentor sounds more like a circled stage.
It is very tempting to get the K10, but personally, it is mostly due to the unique design (it just looks like a piece of art). Sonic-wise, i cant say much more about how good/bad it is as I didnt spend enuf time with it, and I didnt try it with any aftermarket cables.
When it comes to sound preference, it's hard to make a generalized suggestion, personally, i wasnt too impressed with 334, but the scale can tip the other way depending on what type of music/player u use/listen, and not to mention how much coloration/MSG you like in your sound.