I just tried an h265 encode and the results were very good. The suggestion is that it offers the same quality in half the filesize and it seems to do pretty much that. MKV also offers the same, but I've never found it user-friendly.
It's a good bit slower at converting though and the files will only work on updated players such as VLC, so I'll keep it by for now, but it looks to be the codec of the future.
Imagine youtube being able to halve the bandwidth it uses.