I don't own an iSeries but I've looked at them in the past, they definitely seem like a good contender for offering better-than-average protection at a less-than-premium price.
My only other observation (and I apologize for harping on this; frequent readers of TB will note that this is my personal bugaboo/soapbox) is that I believe SKB is misusing the "ATA" nomenclature. I'm pretty sure any case with a non-recessed handle cannot meet ATA Spec. 300, Category 1 (which is the standard for multi-use musical instrument case designed for air travel). Doesn't mean the case sucks or that the handle will break, just means that A) your options for reimbusement should the case contents ever get damaged are limited (versus if the case was actually demonstrably able to meet ATA Spec. 300, Category 1) and B) SKB is guilty of false advertising.
But I'd certainly rather fly my bass in an SKB iSeries case than anything lesser.