At the price of the X1, I prefer the K7XX. If you can spend a bit more, I prefer the X2 to either. (YMMV)
^ @ 169 dollars?
Yeah. The K7XX is $199 new. For $30 more, I personally think it's a better choice. The X2 is $299 and I prefer it to the K7XX. I don't know that it's 50% better than the K7XX but if you can afford the jump up (or find a good deal on one), I do prefer it overall. Not everyone agrees with me on this one tho.
As always, the best way to tell is to listen for yourself.
Thanks for the replies everyone. So is it necessary to change out the pads on the 150? What would people recommend as replacement pads?
It's not necessary, no. But it's a nice bump in comfort, if you feel like you would like that kind of thing.