Connectivity with client Telcos works perfectly way and administration is simple.
I think it's the perfect Firewall for SME.
10 out of 10.
Version 5515 is better than 5510 or 5505.
If you know how to use Cisco IOS, it's easy. Otherwise, you will find no way
of configuring it with ease.
Go for the complete bundle, it's a one time investment only. Otherwise, in the future you will have to buy other tools as licenses for some add-on services.
I would go for bundle licenses and hire a Cisco engineer for implementation.