Krell 300 il or 400xi or ? What would you do ?

I think what I want to do is get a pair of Magnepan 1.6 for my fronts and use my MMG's for the rears. I like what I am hearing with Magnepan.
I want to use a Integrated amp. The Krell 300il seems to be a good canidate and or the 400Xi.
Trying to understand why the 400xi has a lower list price but has more power then the 300il that has a higher list price but offers less power?
What am I missing and not understanding in these 2 units.
Open to suggestions and help on this.
Thanks,
Dave