there's no particular reason, this little amp has punched above its weight all the time i have had it. i agree that it works well with the focal's.
the amp was the "best" i could afford at the time. i bought it ex-dem at better than half price. i've teamed it up with a p85 in the past and it did well. there is tons of detail. a vastly underrated little amp.
several months ago, i started to upgrade, firstly buying the Apollo CD player, which is possibly the best thing i've ever heard. replacing an arcam dv79 which had been on dual duties, then, i replaced my Mission M35i speakers, i'd had them from new, and sold them so i could buy the Focals. So the little arcam is the last part of my original setup to replace.
i'd had it around 7 or 8 years, so i just fancied a change. hopefully to something a bit better.