But Windows 10 will be available for the Surface 3 as well. So I don't see how that makes the SP4 "worth the wait".
Windows 10 in its current form has some of the tablet-centric features removed... it is my understanding that the Charms bar is no longer present. Also, it isn't Windows itself that makes the Surface sub par as a tablet but the lack in the quantity of quality touch-optimized Modern UI apps. That is not going to be resolved with the introduction of the SP4 or Windows 10.
I think you sound a little close minded to the whole Windows 10/SP4 think and I am not here to convince you. I am not interested in tocu apps. I want a full operating system that will run AutoCad and Quickbooks which Apple can not produce.
Enjoy your iPad.