Disk Utility vs VeraCrypt

It offers the best integration, ease of use and support with OS X.

You can create a disk image that requires a password to mount. It can use a different filesystem than OS X, like exFAT, that can be used to move files between Windows and OS X. Additionally, you can encrypt file volumes by right-clicking and selecting encrypt.

Veracrypt is an on-the-fly encryption tool. Meaning that it decrypts files only when they are needed and that the files are otherwise kept encrypted the rest of the time.

This project is free and users are encouraged to donate something to keep the project going.

Supports AES, TwoFish and Serpent encryption cyphers.

The source code is open to review. It has already had a security audit and it did well, with small problems fixed by authors within days of being reported. Its predecessor source, Truecrypt, had a detailed audit that found its capabilities sound, completed (ironically) shortly before the TC folks decided to call it quits. Anyone skeptical or curious about what it does can see how it works, at the gut level.

Most Intel and AMD (and possibly other) CPUs have AES specific instruction sets, so you needn't task the CPU during the en/de/crypt process when using AES, VC throughput is as if the code were in 'firmware'; you can see the effect if you choose anything but AES as your cipher.

It can create containers (like a encrypted folder) which is very useful.

Veracrypt is in active development with constant and regular updates and several external audits in the planning stages.

Veracrypt is supported on MacOS, Linux and Windows.

It's easy to understand and use.