Size doesn't guarantee any benefit. It's all about the efficiency of the core in relation. The quality of the core, which you can't see, can make a huge difference to efficiency.
I'm not suggesting the Wagner setup is not as good, or is better either. Without appropriate objective data to support, which is more than available on either the Wagner or Forge website, no conclusion can be drawn IMO.
BTW... Aoon asked me what to log when he was looking to compare the two intercoolers, which I'm pretty sure he hasn't done yet. If he had he would of rammed the results down my throat on whatsapp!