It really comes down to your ears. The 350 is an amazing amp and with an ACT2 you should be happy. Back to your ears...do you want tubes, clarity, detail, music or all of the above. The 140 is not a 350. It has a natural midrange but not all the robust and air of the 350. But, that is my opinion. It is my understanding that the LP70S will not have as much headroom as the 140 but is faster and more detailed and maybe even sweeter...teflon caps? But here is a new twist. CJ will ship the Premier 150 this spring. Using their terminology, it is a control amplifier. If I remember and have this right, it is half of the Premier 350 with the swtiching and volume control from the Premier 18. It has no gain and the volume control attenuates output. So, it is quasi passsive or a non-integrated integrated. It sounds lovely. I like this amp! One box. Great sound. More than enough power.