Getting more drives, should I make a new volume?

[Naesstrom]

So, tomorrow I'm getting 2 new 8TB WD Red's since I got tired of my drives being full all the time! (to many good movies this year) :D
Current setup looks like this:

All in one volume, running mirrored since that's what I started with years ago! Since I only have 2 new disks to increase the storage with I'll have to go with mirrored again from what I've read. The question is there any benefits of making a new volume instead of just increasing the old one?

 

[garm]

Due to unbalance you will get better performance if you redo your entire pool. Adding a new pool will give you the same performance as adding the drives as another mirror. Adding another mirror to your existing pool will utilize the space more efficiently and that is what I would do. I have basically the same layout as you in my primary NAS

 

[Naesstrom]

Ah ok, I'm not able to redo it all since I need someplace to store the current 12TB :D Started with 2x4TB, then another pair... after that the 6TB started getting cheaper and now 8 :D
Thanks for the reply, I'll just increase my current one with the new ones tonight then!