Buying Decision: Astaro vs Fortigate Throughput

I want to procure an hardware appliance for my office of 100 users. And there is a battle happening between Astaro and Fortigate specifications.

We are comparing Astaro 220 with Fortigate 300C (for similar pricing) and could see that Fortigate has 8 Gbps of firewall throughput while Astaro displays 3 Gbps. What does this mean?

Also Fortigate exhibits 2 Million concurrent connections while Astaro does 300,000 connections. How does this affect our operations?

We are a group of 100 users, 60 Mbps WAN uplink, a web server hosted in-house, most of the users making Skype voice calls, and moderate VPN usage.

I am interested in how Astaro defends itself for making me buy it.
Thank you for any insight.