Bartok - Sonata for two pianos and percussion

Yesterday another audition of Bartok's Sonata in the Argerich/Bishop version. I've listened to it 6-7 times over the last couple of months but it continues to be an elusive piece. The overall idea seems to be clear enough: an introductory movement full of nervous tension, a mysterious slow movement and a boisterous, almost circus-like finale. But there is so much going on, both architecturally and texturally, that I never seem to be 'getting' it. The experience with Prokofiev - much more expansively lyrical and loosely woven - is obviously different. Even his most complex sonatas and symphonies fit snugly. I feel I know my way around them. But I'm not giving up on the Bartok sonata. I'll continue to chip away at it.