Performance concern: StringCollection vs List

I would personally prefer to use List<string>:

• No need to remember one specific type just for strings
• It implements the generic IEnumerable<T> rather than just IEnumerable, and thus supports LINQ
• It’s supported in SilverLight
• It’s more idiomatic for most developers (IMO)

I would be really surprised to find StringCollection to be significantly faster than List<string> – see if you can back that up with numbers. My only cause for hesitation is that GridView could potentially have hard-coded support for StringCollection to make it fast with that type – but that sounds pretty unlikely to me.