Multiple Shared Webhosting Accounts vs. 1 VPS

hey,
are there any disadvantages on using 1 VPS to host 20 microniche sites instead of an shared webhosting space for each project.
especially in focus of ranking.

one danger i see is the the security aspect. if you forget to harder and update your VPS it may get infected by malware which could have heavy effect on the niche sites / on the revenue.

your 2 cents?

Max, why don't you consider a Reseller account.

I would avoid having too many shared hosting for 2 reasons :

1 - You can easily get your site limited ( down ) once you start getting really traffic, all of these unlimited packages are actually very limited
2 - Cost, paying a hosting company per site when you have like 2 is very costy.

If security is a concern, I would prefer to go with CloudHosting as it is generally more secure