I like search.cpan.org in the most part. However, one of the things that annoys me about it is that it ignores CPAN indices. CPAN indices are the things that tell you what module is in what distribution, what distribution is the latest version of a module and who the authors are. More importantly, the indices are used by CPAN.pm and CPANPLUS.
So it annoys me when search.cpan.org ignores the CPAN indices. For example, I was looking for a quick module to find the machine's IP address, and I find Sys::HostIP. Looks neat, so I download it and test it and the module doesn't work like the docs say it should. This is because search.cpan.org says that Jonathan Schatz's Sys-HostIP-1.3.1 is Sys-HostIP on CPAN. However, the CPAN indices don't agree. If you look at 02packages.details you'll see that what CPANPLUS actually installed for me was FIVE's Sys-HostIP-1.0. CPAN::Search::Lite gets it right, and even points it out in the FAQ.
I've pointed this out in a past, but I reckon it's worth a rant. search.cpan.org shows you things which aren't really CPAN and aren't what CPAN.pm or CPANPLUS will install. I recommend using CPAN