A question about 9.04 ubuntu

Hello all--I installed the entire OS to a USB ext drive--it works great--When i turn on my PC--i get a menu that askes if i want to boot from the USB drive or the HD--all works great.. My question is--Are there any disadvantages of running ubuntu on an EXT drive plugged into the USB port?

IT seems to runs flawless..... I have 4 gigs of ram in my machine and the USB ports are USB 2.0

Thanks for any input.. Have a great day!!!! MARK

To me, the main disadvantage would be I/O performance. USB is slower than the bus on a modern internal hard drive. Do your external drive and computer have ESATA ports? Using that instead of USB would make things load faster.