ASA5580-20 with IOS software

[frogmanclay]

Does anyone have experience using an ASA5580-20 with IOS software? On top  
of that, using it as a headend for an Easy VPN solution? I am trying to  
figure out how many sites it can safely support, also are there any major  
problems with it? All of the documentation on Cisco's site only talks about  
using it with ASA software, but then it only supports Legacy Easy VPN and  
not Enhanced Easy VPN. In order to support Enhanced you have to run IOS.

Thanks for your time,
Clay