Actually, I've found the performance of my Xen VPS much better than a dedicated server at The Planet. Most likely that's because the dedicated server had just one IDE disk and the Xen host has a fast SCSI RAID array. Dedicated hosting gets pretty expensive when you get into SCSI drives and RAID but it's really important to consider your performance and reliability needs.
Scritti inglese molto bene! Complimenti.
grazie ;) ma parlo molto male.
Allora, deve abitare in America, Britania, Canada, etc. se vuoi parlara bene. E' troppo difficile imparare da solo. Ma se pua scrivere bene, va bene cosi'.
Btw, you can see that I write like a child. "Scritti"? Scrivi! :-(
It's very important to have a good Linux distribution like Debian or Ubuntu where you can install/upgrade things in few seconds with apt-get.
Also it's important to have root to be able to install different apache modules, install cron jobs, be able to manage the firewalling in case of attacks (I saved myself from a DOS thanks to a Tcl script + iptables one week ago).
Virtual servers are cheap but the performance may not be bright.
p.s. I suggest to use a very low TTL for your DNS records so you can switch ASAP if there are problems. Also to try to "packetize" your application is important in order to make sure you can install without too much problems your code in a different host in little time.