What's the approximate room size, and the expected use % movies vs music? Will you be doing any multichannel (SACD/DVD-A) music? The nucleus lacks a tweeter, so it' sound will not be quite as crisp as something like the LM1 in the highs.
On paper, the Nucleus doesn't match up to the LM1, actually. The LM1 says -6dB at 65Hz, which means -3dB somewhere around 75-80Hz, and 91dB efficiency. The Nucleus says 100Hz, and guessing that is -3dB, that means it will not go as low as the LM1. It also has a relatively low sensitivity of 87dB. This doesn't tell you how the sound though.
The ideal match would be another set of 705s or the DS7 from the same family, but if you are looking for something small, the LM1 is probably the better choice of those.
I've heard the AGs briefly, and they actually sound pretty good. I have not heard the LM1s.