I have used both.IR4 and 5 --Frankly , I have found it difficult to manage and control. The least movement is exagerated . One has to accept a fairly long learning curve. -- It IS a unique system , but it has also been one of the most frustrating piece of equipment I have ever purchased for FSX.
I have solved the problem for myself by installing three monitors , upgrading my video card and power source. BEAUTIFUL !! --if not a bit expensive. I am a former pilot ,(many years ), and I have used flight simulation since almost the beginning.-- The multiple screen sysytem is "nearly" real.
Highfly