Hi there (again)
I'm not aware of anyone owning this amp on here, so in the possible absence of informed comment, I'll give my opinion.
I have not heard this amplifier, but am certainly aware of it....so please take my remarks in the light of this.
From what I've read, the Di 150 is a very neutral amplifier, which would be the exact opposite of the Inpol. It will not flatter bad recordings and won't, for example, have the emotional presentation of say, a Lavardin.
It would worry me that it could be a bit much with the Focal, and would need a speaker with a touch of warmth (eg. Sonus Faber).
This is complete conjecture, and shouldn't put you off demoing. IMO You should be looking at an amp with a touch of warmth, a musical sounding mid-range, and a sweet but detailed treble.
The best I've heard Focal sound, was on the end of the AMS35i (no surprises there then).....would you consider putting this on your list?