Funnily enough I haven't listened much to the Ardittis since I heard them playing, um, the
Grosse Fuge at the Wigmore a couple of years ago. Horrible it was.
They coupled it with Nancarrow and Ligeti (and the obligatory
Ainsi la nuit) but appeared to have decided that the Beethoven was written in a pitch language which didn't require tuning.
I have to say that their account of the piece did little for me either. I first heard them play it in that seven-programme series featuring the quartet and its work chaired by Michael Berkeley God knows how many years ago (this, of course, in the days when Rohan was still with them) and, for all Irvine's remarks about it being one of the most modern works in their repertoire, I found their performance of this sometimes angular, always big-boned not-for-the-faint-hearted work dismayingly tentative (and yes, one could call into question certain intonational issues in that, too); funnily enough, I've not heard them play it since, so I cannot comment on how their account of it may or may not have matured. I also suspect that they must be one of the very few - if not the only - ensemble who has that movement but not the remainder of the B flat quartet in its repertoire...