I used to attack the K1K as I thought it was the only specialty can to hit top-tier status (the GS1K, another specialty can, is a clear opposite in general rankings). Properly amped I'm not sure I feel the same way any longer. I may still end up preferring other general purpose cans (often due to practical considerations), but I think the K1K can certainly hold their own in any case. Again I wouldn't include a lot of "recommend amps" in the "proper" list. There is a bass limit, but it's lower than I'm guessing most have heard and if the signature is "too midrangey", harsh or only about "sparkling highs" there may be a problem. That said several phones can soar if the hunt is long enough for synergy and I don't fault anyone abandoning the pursuit before reaching happiness elsewhere. The LCD2 or JH13 joy is much easier to find.