Everybody that has been a KDE user for the last 2 years knows Nepomuk and its bad reputation, maybe it was desired in the past, but no more. This morning I decided to get my Nepomuk up and running again, and I have to say that it is impresive! just take a look at this video:
The only thing I had to do is modify a kernel configuration, but I had to do it because my distributionb (ArchLinux) didn't for me, others like Ubuntu or OpenSuse have the correct value.
fs.inotify.max_user_watches = 524288
If you get a value such 8000 then you have to change it, to do it:
echo "fs.inotify.max_user_watches = 524288" >> /etc/sysctl.conf
The only thing I'm missing now is a good plasmoid (Crystal to the rescue?).
Update: I'm using trunk (4.6), but afaik Nepomuk should be as fast as in 4.5
Dolphin searchbar is a feature found in 4.6 (to be released in 2 months)
If you update the parameter using sysctl command remember to restart nepomuk.