Razer CEO Min-Liang Tan appears to be making a habit of communicating with fans through his Facebook page regarding decisions and upcoming updates for the Razer Phone. After discussing the lackluster camera a few days ago, Tan is now addressing why the phone doesn't have a headphone jack on board. It's a pretty solid explanation.

Tan gives a number of reasons why the Razer Phone doesn't have a 3.5mm jack, which include battery size, audio quality, and thermals:

By removing the headphone jack - we were able to increase the battery size significantly (I estimate we added 500maH more), improve thermals for performance and a whole lot more.

The trade off was not having the jack - but what sealed it for me was that we were able to get audiophile quality sound with the dedicated 24-Bit THX Certified DAC adapter - and I made sure we included that with every phone. Which basically means we give even better quality headphone audio for those who want to hold on to their analog headphones.

He also mentions in the comments that a custom battery would have delayed shipping, raised prices, and increased risk of battery issues. In short, you're sacrificing convenience of not having to deal with a dongle for a larger battery, superior headphone quality, and better performance. The 24-bit adapter is included in the box, so just make sure not to leave it anywhere.