iTunes slow with large music library?

I was just posting to see if anyone else had any issues using iTunes with a large music collection (say 80Gb+ of mp3s). iTunes seems to grind to a halt with a large library and to me it seems because the library is stored in a flat file (an XML file, the location of which I forget). Winamp and WMP10 seem to be quite efficient at searching a large library which leads me to think they have some form of light database running to achieve this performance.

Anyone else had a similar issue? found a way around it? It's a shame because it's the best software to interface with the iPod (not surprisingly). Just wish it handled large collections better...