I think it's a given that MP4 is the current standard for video, especially if your going to upload to U-Tube. A good 1080p recording is going to cost Gb's. No way around that; the codec and the resolution are the ultimate determining factors. Your video will never be any better than the compression codec and resolution you shoot it in. Taking a 720p MP4 video and editing it to a 1080p MP4 video won't help either. (Don't ask me how I know this!) Video's, particularly HD vid's are large memory sinks by nature.
The keyword here is resolution, in pixels. If you want detail, its going to cost memory.
I kind of think of it like this.............I want to show you all a good vid of my route. To me, as I watch it on my computer, it's a great juicy steak I'm serving up. (I will assure you that it is!) However, once I start recording, it goes through a grinder; rendering only hamburg! It's going to come out hamburg, no matter what. I can only control the quality of that hamburg. Newtonian physics has confirmed that 1lb. of choice siirloin going into the grinder = 1 lb. of ground beef coming out of the grinder......agreed?
However, it's not the same steak coming out of the grinder, it's all broken up into little pieces (digitized) and some of the pieces are missing (compression). If I use a 480p grinder I might only get a half pound of ground beef back, A 780p grinder will give me more, and a 1080p grinder will give me even more. But I will never, ever, get a full pound of ground beef from that 1lb. steak.
Well, where did all that other beef go? Look down and pat Poochie, (woof, woof) he got it, and you ain't never gonna see it again.