Firstly, BTRFS is just a different animal in comparison to EXT4. To put it succintly, EXT4 is a filesystem, where as BTRFS is a filesystem integrated with a volume manager. If you've ever worked with LVM2, then you have experience with a volume manager.
Whether you should adopt BTRFS over EXT4 is subjective; Only you can answer that. It's not merely that one is better than the other. To help you decide, I recommed you go to https://btrfs.wiki.kernel.org/index.php/Main_Page, scroll down to the Guides and usage information section, and read all of those articles; Except the article on RAID, which you can probably skip. That will give you a sense of that BTRFS is about.
Regarding the partitioning scheme, there are two things at play here: the disk partitions and the BTRFS volumes. First, I'll re-map your old partitioning scheme, and then explain the reasoning.
Note: The actual partition numbers are irrelevant, it's the fact that it's a partition that's important.
/dev/sda3 / subvol=/volumes/root
/dev/sda3 /home subvol=/volumes/home
Here are the important things to note:
- /boot and swap are partitions.
- / and /home are BTRFS subvolumes on the same BTRFS filesystem.
- There's only one partition with a BTRFS filesystem.
BTRFS doesn't support swap. It's a filesystem, not a partition so making it a swap partition doesn't make sense. As of this writing, BTRFS doesn't support swap files, but you can use a loop-mounted file and pay the performance penalty. Point being, it's best to leave it as a partition.
According to the documentation, if you're using Grub 2, you can put /boot in a BTRFS subvolume rather that it's own partition. I'm still on Grub 1, so... there's my reasoning :)
The main diversion here from EXT4 is in how the data is partitioned out. In short, instead of using multiple partitions, whose sizes must be chosen well in advance, you can dump it all into the same big partition and use subvolumes to divide things logically.
BTRFS currently doesn't have native support for encryption, but... there are ways. See here