Better to use 2 bigger Azure VM's or 2 smaller Azure VM's for RDS?

Greetings,

I need to setup a RDS environment in Azure.
I'm in doubt about which VM's to use for Session Hosts.

Option 1: 4x DS2 Standard VM (2 cores, 7GB, 6400 Max IOPS) = € 745,-
Option 2: 2x DS3 Standard VM (4 cores, 14GB, 12800 Max IOPS) = 744,-

Pricing is exactly the same. Biggest diffrence is Max IOPS per server. Total is all the same.
So what would be better: 4 Servers with 2 Cores, 7GB and 6400 Max IOPS or 2 Servers with 4 Cores, 14GB and 12800 Max IOPS?

What would you guys do and why?

Kind regards,

Robin