WHMCS beats CE by FAR!! WHMCS has a lot more features and than CE, and keeps better records of your clients. Not to mention it's just a lot better looking!
I say WHMCS. I run a web hosting business and must I say out of all the demos I used before WHMCS none of them competed to WHMCS. I have been a WHMCS customer for about 7 months now.
As a newbie to Web Hosting, it only make sense for me to start here. The problem is see with the whole web hosting reseller gig, is initially you have got nothing but costs and all sorts of technical aggravation. The problem I see with Client Exec is it seems like (by their own documentation) they only support a few domain registrars and I do not have a clue if they will (or can easily be customized).
My question is if you have only been in the game as a web hosting reseller wannabe for like two months would you go with ClientExec which I apparently have for FREE thanks to my plan, or pay the extra monthly money (or try to buy the WHMCS license outright) from someone getting out of the web hosting biz for a deep discount?
For start clienExec is ok porgram. Sure WHMCS is more powefull, but for start is ClientExec great, special if you get one for free. Most company who offer reseller packages also offer ENOM domain registrar, clientExec support ENOM.
I'd have said WHMCS without doubt a few months ago, however now ClientExec really has changed (for the better!) The new update (I believe 4.1) has a new front end which looks quite nice and the back-end was completely redesigned recently and so it's much nicer than it used to be.
I think the support system could do with a bit of work, but apart from that, for what we want to sell, ClientExec is very good!
WHMCS would be a good choice especially with their new v5 update coming soon. You should consider whmcs as it is reliable and it also supports whmphp reseller plugin.