Great advice. Lack of server management skills is what keeps so many in the reseller ranks from going VPS.
The problem with VPS i faced when i had a vps is
1) You need to take care of server management
2) You need to pay for the control panel license fee
3) Your disk space will be too limited, unlike reseller hosting you may not get 100 GB or more for less than $20
4) If you do some mistakes with your VPS or use it for purposes which are not approved by your host your host, your VPS will be lost, no chance of getting data is you dont have enough backup
5) Not many VPS companies offer managed VPS, its a big issue with setting up security
6) Cannot be used for Reseller hosting, not affordable.
The advantage is
1) You decide everything in the vps its like owning a small dedi.
2) You can run any softwares which are permitted for general usage in VPS
3) USeful for sites which exceeds the traffic of Shared hosting
4) Fast loading and control over many factors in the site.
The above is my personal experience.