Truth being said your server specs are very poor, as
@Tracy Perry said it's very probably that your old VPS outperformed your current server because maybe it was on a dual quad-core node with 4 HDDs in RAID 10.
The output of the command I asked you to run says that your HDD copied the data at 93MB/s which is the average speed of an HDD so at least you know that it is not the problem.
I can guarantee you that the problem is your CPU and you can verify it in a very easy way. Install an add-on and let it go through the admin template rebuild again and while it's running open your SSH client, login as root and run the command "top". At the top left corner you'll see your CPU usage, and at the top right corner you'll see your load averages. Also, you'll be able to see your RAM usage... it's very probably that your server is swapping and that make things even worst.
With 2GB of RAM WHM/cPanel is going to eat a lot of resources... may I ask you how much are you paying for the server? Here are some suggestions that will outperform your current server performance:
Future Hosting VM3
2GB RAM, 50GB SAS, 8+ CPU cores equal share and 3TB bandwidth
$33.96/mo with coupon HOLIDAY2014
Source:
http://www.webhostingtalk.com/showthread.php?t=1435233
KnownHost VPS2
2GB RAM, 70GB RAID 10, 8+ CPUs equal share and 6TB bandwidth
$29.75/mo with coupon KH15LIFE
Source (outdated plans):
http://www.webhostingtalk.com/showthread.php?t=1411042
They recently updated their plans keeping the same prices (they do it every Christmas):
https://www.knownhost.com/managed-vps-packages-2014-compare.html
Plus they both come with WHM/cPanel VPS Optimized (minimal resource usage) and are managed so in case you need help with your server you have support available 24x7. Future Hosting and Known Host are excellent VPS providers, you can search for reviews at WHT. I have used both and I was very happy with them.
I haven't used eva2000's CentMin all-in-one installer however if you want to learn how to manage your server (and get rid of WHM/cPanel soon) I suggest you to install Apache (or nginx if you want), PHP, MySQL (or MariaDB if you want) and configure everything yourself, that way you'll learn. As for the DNS you can use CloudFlare's free plan which provides free DNS management.