I can give you my best references for Fr3d and his team.
Our server used IL depmax64 for long time and now we switched to IL advext64. We are very satisfied with this extender because:
1. extender is stable
2. regularly released updates
3. scripting support
4. new custom features
5. fast problem solving if any appears
6. and of course Fr3d is a nice guy :p
I can recommend Fr3d and his teams services because you can not find anything like this :)