I think it really depends with the ITX30, I've seen Intoxicated Puma's test results and I donated my ITX30 for the testing originally not by him as I thought so little of it. The problem as I saw it was the footprint of the base was small(didn't completely cover the IHS), so depending on IHS etc I think results can vary significantly as heat transfer is not ideal. I had to shutdown stress tests immediately on my 3770K, while the L9I which he tested as worse cruised for awhile in the same test(multiple paste applications). To illustrate, pic below of AXP100 next to ITX30. It could be there's a better version out in the wild but I haven't seen evidence of it. The original AXP100 is still about the best LP I've tried just too tall for my cases now.
I have an early IS-30 but couldn't use on latest build as the original AMD brackets were too long(also fit AM3, they are sending me the AM4 only version) and interfered with a VRM and so couldn't mount it. Instead I ended up using the AMD Wraith Stealth with a Titan 95x15mm fan which has turned out to be pretty awesome, 37mm height. The IS-30 seemed real nice probably give it a try if I upgrade to 3x00G APU.