@stoosh
I think you will end up keeping the GS 4

You loved the GS 3 LTE and the GS 4 has many nice improvements overall, however, touchwiz will ruin it for you, so until you can root and flash a stock ROM or whatever, you might still prefer the N4.
The m4 "could" be an excellent device, however, it "has" to be priced correctly, any more than £350 (if the specs are true) then it will be a fail in my eyes. And yup, I am quite excited about it, only main downside for me is that the screen will be the same size, do want bigger

If they use a SLCD 3 or the newer SAMOLED panel then battery life should be better than the one S, so it should be very good then
Indeed, I think a lot of people are going to be underwhelmed/annoyed come the announcement of the X phone.....
Another issue

Haven't been following the GS 4 lately so that is the first I have heard of that! The GS 4 will be using qualcomms S4 audio stuff and pretty much every phone that uses it from the last year has very good audio, haven't noticed any issues with my S, audio quality is great, both loudspeaker (for a phone) and earphones, although I am no audiophile
Pretty much, the only thing that "really" sets the one/GS 4 apart from last years flagships is the one's speakers and the screen of the GS 4 and one (more of a difference between the GS 3 and GS 4 screen than there is between the one X and one screen) imo, sure the cameras amongst other wee things have improved, but it isn't exactly a "worthwhile" upgrade "overall", OIS is superb though and the benefit of the one camera i.e. low light conditions etc. are great and hopefully has forced OEM's to put more serious thought into their cameras rather than just solely concentrating on the MP number now.