Feature-wise Server 2012R2 Essentials is more impressive. Things like Health Reports, Hyper-V Support, Client Full System Restore (Restore from backup, bare metal over the network).

If the practice is just starting out and plans to use AC 6.6 or above, then use 2012R2 Essentials. I've been using Server 2012R2 Ess/Standard for my recent deployments. If you're planning on 6.3.3, use SBS 2011 Essentials.

But if you want Exchange and Sharepoint, SBS 2011 Standard is still the best price. That will be supported until 2020.

With the demands of software plateauing, people aren't upgrading for a longer time. They are stacking more and more on one box. That's why virtualization is becoming so popular. 95% of the time your CPU is just sitting there, bored. So people stack a bunch of Virtual Machines on them.

SBS 2011/2008R2 reaches End of Life 2020 = 5.5 Usable Years
Server 2012/ 2012R2 reaches End of Life 2023 = 8.5 Usable Years

I would say use Server 2012R2 Ess/Standard

Sandeep Luthra | LTMedical.net
2023 Practice Systems now available