I have been in this business for a while and I think that if someone is able to denigrate one of the billing software out there (no matter which one) and call it as a novice control panel, it is that he is himself probably a novice and probably does not know how to write a single line of code.
Now the positive stuff
I think that every control panel have their own use and specialty. Each one can be good in their own area. Here is a small drop down :
1- Modernbill : Still the most popular, overloaded with useful features for hosts that would like to manage everything in the same place, lots of bugs but lots of support. However since MB5, I cannot recommend this one unless you do use MB4. If you sell dedicated servers unless you are managing it very well, stay away at all cost ! Very good for shared hosting, resellers and add-ons.
2- WHMCS : A new comer to this industry, sounds like a hype to me, personally I never used it as their demo did not quite impress me and I did not like the way people are integrating it to their site. I once did business with one hoster using WHMCS and it was a real pain for me as a customer. It is a personal choice.
3- Clientexec: Has been around for a while, almost as long as modernbill. Good for shared hosting, resellers. Lack of domain name management features (even tho you can register them). Have good community and support. Since v3, it is easier to add addons, still room for improvement.
4- Ubersmith: Ideal for dedicated servers business and datacenters. It is my personal choice, it is just perfect in everything it does. However be prepared to use one machine to handle it as it is a beast.
5- WHM AutoPilot : Nothing to say about it really .. I tried the last version and it was a real pain all the way.
These are of course my personal comments. With my past experience with these billing software. I am myself a coder and I highly respect the work of all the developers trying to make this business a better world for all of us, I think everybody should do the same and give them credits for what they diserve.
My 2 huge cents