Personal Experience (Score 1)

I originally tried to convert an application from Oracle to MySQL 5.0. Very simple app, though it had some views in it. The views performed much slower than the straight SQL did - microseconds vs 10seconds plus. I then converted to PostgreSQL 8.0 and everything worked fine. As some one with years of database experience with Oracle, SQLServer, and others, I found Postgresql, at face value, to rank up with both of them in many respects, while I found MySQL to be somewhat limiting. MySQL's flat out speed is of no value if it can't provide the basic requirements of a relational database. While I don't have heavy-duty performance requirements, everything else about PostgreSQL seems top-rank. Documention, stored procedures, SQL adherence, advanced storage mechanisms, etc. were all there. And when the next, great open source database comes along, the standardization that it provides will make it all that much simpler to port yet again!