Hi, Gerard...
Security - I don't think anyone would disagree that SQL Server is a more secure DB than VFP. VFP was never ever designed with security in mind.
Speed - On small or medium sized databases, one might be able to prove that VFP is a tad faster...."might". However, as databases grow, SQL Server's speed will usually win out. Also, SQL Server has text indexing.
Ease of Use - in many ways a subjective claim. They're different. I personally don't consider either one to be easier or harder.
Robustness/Scalability - no contest...SQL Server wins this one. Again, I doubt anyone will argue. SQL Server has a much greater capacity for storing larger databases.
Ease of getting data in and Out --- the SQL language in VFP has always lagged behind SQL Server's compliance with the ANSI SQL standard and other language features for querying.
VFP as a database is a good product...SQL Server as a database is far better.