@hsw—Not hard at all. I set levels and crossovers in pairs, from the bottom row up. Crossover level is lowest for the bottom pair, second row a bit higher and third row is higher again. Levels follow the same pattern from low to high, but are closer together. Then after those were done, small tweaks to each row as needed. I found the level control to be the most sensitive and it had the biggest impact, but it was not hard to match with the volume of the main speakers. I have a small room (10 x 14), so YMMV. Maybe an hour’s time, max.
The line array concept was a big plunge for me, but the results are spectacular: wider soundstage, bigger image, better clarity, and most significant to me, more heft/substance/weight (without any hint of softness) to the rendering of each note, tone, vocal, or percussion—across the whole music spectrum really, which to my ears has always been one of the hallmarks of live music. Not a cheap upgrade by any means, but the ROI is stunningly good.