On the broader topic: No, I don't think it is the best product on the planet, but using the advanced features in oracle or MS-SQL will give you performance/ease of development at the price of vendor lock in, something I remember JVP to argue strongly against (Couldn't resist <g>). I actually don't recall JVP making that argument (not saying he didn't, I just don't recall). I know that John used Oracle-specific features in some of his Oracle work (perhaps because he had to).
I freely admit that I take full advantage of the tools and capabilities in MS SQL.
And yes, I know that changing backends in an Enterprise app is not done very often and seldom planned by the developers - but it *does* happen, for instance in mergers/acquisitions sometimes the large parts of the structure is converted. That's a good point, M/As do happen - however, with all the integration tools that are available, odds are good that at least in some instances, databases wind up staying put.